Functionalized monomers for synthesis of rubbery polymers

ABSTRACT

The present invention relates to a rubbery polymer which is comprised of repeat units that are derived from (1) at least one conjugated diolefin monomer, and (2) at least one functionalized monomer of the structural formula:                    
     wherein the R′ groups in repeat units and in different repeat units can be the same or different and represent hydrogen atoms or alkyl groups containing from 1 to about 4 carbon atoms, wherein x represents an integer from 1 to about 10, and wherein the R groups in repeat units and in different repeat units can be the same or different and represent alkyl groups containing from 1 to about 10 carbon atoms or alkoxy groups containing from 1 to about 10 carbon atoms.

This is a continuation-in-part application of U.S. patent applicationSer. No. 10/624,188, filed on Jul. 22, 2003, which is acontinuation-in-part application of U.S. patent application Ser. No.10/384,020, filed on Mar. 7, 2003 now U.S. Pat. No. 6,693,160, whichclaims the benefit of U.S. Provisional Patent Application Ser. No.60/404,081, filed on Aug. 16, 2002, and U.S. Provisional PatentApplication Ser. No. 60/434,892, filed on Dec. 19, 2002.

BACKGROUND OF THE INVENTION

It is important for rubbery polymers that are used in tires, hoses,power transmission belts and other industrial products to have goodcompatibility with fillers, such as carbon black and silica. To attainimproved interaction with fillers such rubbery polymers can befunctionalized with various compounds, such as amines. U.S. Pat. No.4,935,471 discloses a process for preparing a polydiene having a highlevel of affinity for carbon black which comprises reacting a metalterminated polydiene with a capping agent selected from the groupconsisting of (a) halogenated nitrites having the structural formulaX—A—C≡N, wherein X represents a halogen atom and wherein A represents analkylene group containing from 1 to 20 carbon atoms, (b) heterocyclicaromatic nitrogen containing compounds, and (c) alkyl benzoates. Thecapping agents disclosed by U.S. Pat. No. 4,935,471 react with metalterminated polydienes and replace the metal with a terminal cyanidegroup, a heterocyclic aromatic nitrogen containing group or a terminalgroup which is derived from an alkyl benzoate. For example, if the metalterminated polydiene is capped with a nitrile, it will result in thepolydiene chains being terminated with cyanide groups. The use ofheterocyclic aromatic nitrogen containing compounds as capping agentscan result in the polydiene chains being terminated with a pyrrolylgroup, an imidazolyl group, a pyrazolyl group, a pyridyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, anindolizinyl group, an isoindolyl group, a 3-H-indolyl group, acinnolinyl group, a pyridinyl group, a .beta.-carbolinyl group, aperimidinyl group, a phenanthrolinyl group or the like.

U.S. Pat. No. 4,935,471 also discloses that lithium amides are highlypreferred initiators because they can be used to prepare polydieneswhich are terminated with polar groups at both ends of their polymerchains. The extra polar functionality provided by lithium amides resultsin increased interaction with carbon black resulting in betterpolymer-carbon black dispersion. The lithium amides disclosed by U.S.Pat. No. 4,935,471 include lithium pyrrolidide. U.S. Pat. No. 4,935,471also indicates that preferred initiators include amino alkyl lithiumcompounds of the structural formula:

wherein A represents an alkylene group containing from 1 to 20 carbonatoms, and wherein R₁ and R₂ can be the same or different and representalkyl groups containing from 1 to 20 carbon atoms.

It is also desirable for synthetic rubbers to exhibit low levels ofhysteresis. This is particularly important in the case of rubbers thatare used in tire tread compounds. Such polymers are normally compoundedwith sulfur, carbon black, accelerators, antidegradants and otherdesired rubber chemicals and are then subsequently vulcanized or curedinto the form of a useful article. It has been established that thephysical properties of such cured rubbers depend upon the degree towhich the carbon black is homogeneously dispersed throughout thepolydiene rubber. This is in turn related to the level of affinity thatcarbon black has for the rubber. This can be of practical importance inimproving the physical characteristics of rubber articles that are madeutilizing polydiene rubbers. For example, the rolling resistance andtread wear characteristics of tires can be improved by increasing theaffinity of carbon black to the rubbery polymers utilized therein.Therefore, it would be highly desirable to improve the affinity of agiven polydiene rubber for carbon black and/or silica. This is because abetter dispersion of carbon black throughout polydiene rubbers which areutilized in compounding tire tread compositions results in a lowerhysteresis value and consequently tires made therefrom have lowerrolling resistance. It is also known that a major source of hysteresisis due to polymer chain ends that are not capable of full elasticrecovery. Accordingly, improving the affinity of the rubber chain endsto the filler is extremely important in reducing hysteresis.

U.S. Pat. No. 6,080,835 discloses a functionalized elastomer comprising:a functional group defined by the formula:

where R₁ is a selected from the group consisting of a divalent alkylenegroup, an oxy-alkylene group, an amino alkylene group, and a substitutedalkylene group, each group having from about 6 to about 20 carbon atoms,R₂ is covalently bonded to the elastomer and is selected from the groupconsisting of a linear-alkylene group, a branched-alkylene group, and acyclo-alkylene group, each group having from about 2 to about 20 carbonatoms.

U.S. Pat. No. 5,932,662 discloses a method of preparing a polymercomprising: preparing a solution of one or more anionicallypolymerizable monomers in a solvent; and, polymerizing under effectiveconditions, said monomers in the presence of a polymerization initiatorhaving the formula

wherein R₁ is a divalent alkylene, an oxy- or amino-alkylene having from6 to about 20 carbon atoms; and, R₂ is a linear-alkylene,branched-alkylene, or cyclo-alkylene having from about 2 to about 20carbon atoms, Li is a lithium atom bonded directly to a carbon atom ofR₂; and R₃ is a tertiary amino, an alkyl having from 1 to about 12carbon atoms; an aryl having from about 6 to about 20 carbon atoms; analkaryl having from about 7 to about 20 carbon atoms; an alkenyl havingfrom about 2 to about 12 carbon atoms; a cycloalkyl having from about 5to about 20 carbon atoms; a cycloalkenyl having from about 5 to about 20carbon atoms; a bicycloalkyl having from about 6 to about 20 carbonatoms; and, a bicycloalkenyl having from about 6 to about 20 carbonatoms; where n is an integer of from 0 to about 10.

U.S. Pat. No. 6,084,025 discloses a functionalized polymer prepared by aprocess comprising the steps of: preparing a solution of a cyclic aminecompound, an organolithium compound, and from 3 to about 300equivalents, based upon one equivalent of lithium, of a monomer selectedfrom vinyl aromatic monomers, and mixtures thereof, where said cyclicamine compound is defined by the formula

where R₂ is selected from the group consisting of an alkylene,substituted alkylene, bicycloalkane, and oxy- or N-alkylamino-alkylenegroup having from about 3 to about 16 methylene groups, N is a nitrogenatom, and H is a hydrogen atom, thereby forming a polymerizationinitiator having the formula A(SOL)_(y)Li, where Li is a lithium atom,SOL is a divalent hydrocarbon group having from 3 to about 300polymerized monomeric units, y is from 0.5 to about 3, and A is a cyclicamine radical derived from said cyclic amine; charging the solutioncontaining A(SOL)_(y)Li with from about 0.01 to about 2 equivalents perequivalent of lithium of a chelating reagent, and an organic alkalimetal compound selected from compounds having the formula R₄OM,R₅C(O)OM, R₆R₇NM, and R₈SO₃M, where R₄, R₅, R₆, R₇, and R₈ are eachselected from alkyls, cycloalkyls, alkenyls, aryls, or phenyls, havingfrom 1 to about 12 carbon atoms; and where M is Na, K, Rb or Cs, andsufficient monomer to form a living polymeric structure; and quenchingthe living polymeric structure.

In the initiator systems of U.S. Pat. No. 6,084,025 a chelating reagentcan be employed to help prevent heterogeneous polymerization. Thereagents that are reported as being useful includetetramethylethylenediamine (TMEDA), oxolanyl cyclic acetals, and cyclicoligomeric oxolanyl alkanes. The oligomeric oxolanyl alkanes may berepresented by the structural formula:

wherein R₉ and R₁₀ independently are hydrogen or an alkyl group and thetotal number of carbon atoms in —CR₉R₁₀-ranges between one and nineinclusive; y is an integer of 1 to 5 inclusive; y′ is an integer of 3 to5 inclusive; and R₁₁, R₁₂, R₁₃, and R₁₄ independently are —H or—C_(n)H_(2n+1), wherein n=1 to 6.

U.S. Pat. No. 6,344,538 discloses functionalized monomers andpolymerized functionalized monomers selected from the group consistingof 2-(N,N-dimethylaminomethyl)-1,3-butadiene,2-(N,N-diethylaminomethyl)-1,3-butadiene,2-(N,N-di-n-propylaminomethyl)-1,3-butadiene,2-(cyanomethyl)-1,3-butadiene, 2-(aminomethyl)-1,3-butadiene,2-(hydroxymethyl)-1,3-butadiene, 2-(carboxymethy)-1,3-butadiene,2-(acetoxymethyl)-1,3-butadiene, 2-(2-alkoxy-2-oxoethyl)-1,3-butadiene,2,3-bis(cyanomethyl)-1,3-butadiene,2,3-bis(dialkylaminomethyl)-1,3-butadiene,2,3-bis(4-ethoxy-4-4-oxobutyl)-1,3-butadiene and2,3-bis(3-cyanopropyl)-1,3-butadiene, and methods for preparing suchfunctionalized diene monomers and polymers.

SUMMARY OF THE INVENTION

The present invention relates to functionalized monomers that can bepolymerized into rubbery polymers having low hysteresis and goodcompatibility with fillers, such as carbon black and silica. Thefunctionalized monomers of this invention are typically incorporatedinto the rubbery polymer by being copolymerized with one or moreconjugated diolefin monomers and optionally other monomers that arecopolymerizable therewith, such as vinyl aromatic monomers. In any case,improved polymer properties are realized because the functionalizedmonomers of this invention improve the compatibility of the rubber withthe types of fillers that are typically used in rubber compounds, suchas carbon black and silica.

This invention more specifically discloses monomers that areparticularly useful for copolymerization with conjugated diolefinmonomers to produce rubbery polymers having better compatibility withfillers. The monomers of this invention have a structural formulaselected from the group consisting of

wherein n represents an integer from 4 to about 10,

wherein n represents an integer from 0 to about 10 and wherein mrepresents an integer from 0 to about 10, with the proviso that the sumof n and m is at least 4;

wherein R and R′ can be the same or different and represent alkyl, allylgroups or alkoxy groups containing from 1 to about 10 carbon atoms;(d)

wherein n represents an integer from 1 to about 10, and wherein R and R′can be the same or different and represent alkyl groups containing from1 to about 10 carbon atoms;

wherein n represents an integer from 1 to about 10 and wherein mrepresents an integer from 4 to about 10;

wherein x represents an integer from 1 to about 10, wherein n representsan integer from 0 to about 10 and wherein m represents an integer from 0to about 10, with the proviso that the sum of n and m is at least 4;

wherein R and R′ can be the same or different and represent allyl,alkoxyl or alkyl groups containing from 1 to about 10 carbon atoms,

wherein m represents an integer from about 4 to about 10;

wherein R represents a hydrogen atom or an alkyl group containing from 1to about 10 carbon atoms, wherein n represents an integer from 0 toabout 10, and wherein m represents an integer from 0 to about 10, withthe proviso that the sum of n and m is at least 4;

wherein n represents an integer from 0 to about 10, wherein m representsan integer from 0 to about 10, wherein x represents an integer from 1 toabout 10, and wherein y represents an integer from 1 to about 10; and

wherein the R′ groups in repeat units and in different repeat units canbe the same or different and represent hydrogen atoms or alkyl groupscontaining from 1 to about 4 carbon atoms, wherein x represents aninteger from 1 to about 10, and wherein the R groups in repeat units andin different repeat units can be the same or different and representalkyl groups containing from 1 to about 10 carbon atoms or alkoxy groupscontaining from 1 to about 10 carbon atoms.

One aspect of this invention is based upon the unexpected finding thatrandom copolymers of 1,3-butadiene monomer and 3-(2-pyrrolidinoethyl)styrene and/or 4-(2-pyrrolidinoethyl) styrene having a low vinyl contentcan be synthesized by anionic polymerization at normal polymerizationtemperatures without the need for a conventional polar modifier.

The subject invention more specifically discloses a process forsynthesizing a rubbery polymer that comprises copolymerizing at leastone conjugated diolefin monomer and at least one functionalized monomerin an organic solvent at a temperature which is within the range of 20°C. to about 100° C., wherein the polymerization is initiated with ananionic initiator, wherein the functionalized monomer is of thestructural formula:

wherein the R′ groups in repeat units and in different repeat units canbe the same or different and represent hydrogen atoms or alkyl groupscontaining from 1 to about 4 carbon atoms, wherein x represents aninteger from 1 to about 10, and wherein the R groups in repeat units andin different repeat units can be the same or different and representalkyl groups containing from 1 to about 10 carbon atoms or alkoxy groupscontaining from 1 to about 10 carbon atoms. In such functionalizedmonomers it is preferred for x to represent an integer from 1 to about4. It is also preferred for R′ to represent hydrogen atoms or methylgroups. It is further preferred for R to represent alkoxy groupscontaining from 1 to 4 carbon atoms.

The subject invention further reveals a tire which is comprised of agenerally toroidal-shaped carcass with an outer circumferential tread,two spaced beads, at least one ply extending from bead to bead andsidewalls extending radially from and connecting said tread to saidbeads, wherein said tread is adapted to be ground-contacting, andwherein said tread is comprised of (I) a filler, and (II) rubberypolymer which is comprised of repeat units that are derived from (1) atleast one conjugated diolefin monomer, and (2) at least one monomerhaving a structural formula selected from the group consisting of

wherein n represents an integer from 4 to about 10,

wherein n represents an integer from 0 to about 10 and wherein mrepresents an integer from 0 to about 10, with the proviso that the sumof n and m is at least 4;

wherein R and R′ can be the same or different and represent allyl groupsor alkoxy groups containing from 1 to about 10 carbon atoms;

wherein n represents an integer from 1 to about 10, and wherein R and R′can be the same or different and represent alkyl groups containing from1 to about 10 carbon atoms;

wherein n represents an integer from 1 to about 10 and wherein mrepresents an integer from 4 to about 10;

wherein x represents an integer from 1 to about 10, wherein n representsan integer from 0 to about 10 and wherein m represents an integer from 0to about 10, with the proviso that the sum of n and m is at least 4;

wherein R and R′ can be the same or different and represent alkyl groupscontaining from 1 to about 10 carbon atoms,

wherein m represents an integer from about 4 to about 10;

wherein R represents a hydrogen atom or an alkyl group containing from 1to about 10 carbon atoms, wherein n represents an integer from 0 toabout 10, and wherein m represents an integer from 0 to about 10, withthe proviso that the sum of n and m is at least 4;

wherein n represents an integer from 0 to about 10, wherein m representsan integer from 0 to about 10, wherein x represents an integer from 1 toabout 10, and wherein y represents an integer from 1 to about 10; and

wherein the R′ groups in repeat units and in different repeat units canbe the same or different and represent hydrogen atoms or alkyl groupscontaining from 1 to about 4 carbon atoms, wherein x represents aninteger from 1 to about 10, and wherein the R groups in repeat units andin different repeat units can be the same or different and representalkyl groups containing from 1 to about 10 carbon atoms or alkoxy groupscontaining from 1 to about 10 carbon atoms.

The present invention further discloses a process for synthesizing anamino ethyl styrene monomer which comprises: (1) reacting divinylbenzene with a cyclic amine in a reacting mixture in the presence of analkyl lithium compound at a temperature which is within the range of−80° C. to 80° C. to produce the amino ethyl styrene; and (2)deactivating the alkyl lithium compound by adding an alcohol or water tothe reaction mixture containing the amino ethyl styrene. This process ispreferable conducted at a temperature which is within the range of about−20° C. to about 50° C. and is most preferable conducted at atemperature is within the range of about −10° C. to about 25° C. Thealkyl lithium compound is typically present at a level which is withinthe range of about 0.5 mole percent to about 5 mole percent, based uponthe molar amount of cyclic amine present. The alkyl lithium compound ispreferably present at a level which is within the range of about 1 molepercent to about 4 mole percent and is more preferably present at alevel which is within the range of about 1.5 mole percent to about 2.5mole percent, based upon the molar amount of cyclic amine present.

DETAILED DESCRIPTION OF THE INVENTION

The functionalized monomers of this invention can be copolymerized intovirtually any type of synthetic rubber. In most cases the functionalizedmonomer will be copolymerized with at least one conjugated diolefinmonomer. Optionally, other monomers that are copolymerizable withconjugated diolefin monomers, such as vinyl aromatic monomers, can alsobe included in the polymerization. In any case, typically from about 0.1phm (parts by weight by 100 parts by weight of monomers) to about 100phm of the functionalized monomer will be included in thepolymerization. More typically, from about 0.05 phm to about 20 phm ofthe functionalized monomer will be included in the rubbery polymer. Goodresults can normally be attained by including 0.1 phm to 10 phm of thefunctionalized monomer in the rubbery polymer. In most cases 0.1 phm to1 phm of the functionalized monomer is included in the polymerizationreceipt. It is typically most preferred to include 0.3 phm to 0.7 phm ofthe functionalized monomer in the polymerization receipt.

According to this invention, polymerization and recovery of polymer aresuitably carried out according to various methods suitable for dienemonomer polymerization processes. This includes batchwise,semi-continuous, or continuous operations under conditions that excludeair and other atmospheric impurities, particularly oxygen and moisture.The polymerization of the functionalized monomers of the invention mayalso be carried out in a number of different polymerization reactorsystems, including but not limited to bulk polymerization, vapor phasepolymerization, solution polymerization, suspension polymerization,emulsion polymerization, and precipitation polymerization systems. Thecommercially preferred methods of polymerization are solutionpolymerization and emulsion polymerization.

The polymerization reaction may use a free radical initiator, a redoxinitiator, an anionic initiator, a cationic initiator, or aZeigler-Natta catalyst system. The preferred initiation system dependsupon the particular monomers being polymerized and the desiredcharacteristics of the rubbery polymer being synthesized. In emulsionpolymerizations free radical initiators are typically utilized. Insolution polymerizations Zeigler-Natta catalyst systems or anionicinitiators, such as alkyl lithium compounds, are typically employed toinitiate the polymerization. An advantage of free radical polymerizationis that reactions can typically be carried out under less rigorousconditions than ionic polymerizations. Free radical initiation systemsalso exhibit a greater tolerance of trace impurities.

Examples of free radical initiators that are useful in the practice ofthe present invention are those known as “redox” initiators, such ascombinations of chelated iron salts, sodium formaldehyde sulfoxylate,and organic hydroperoxides. Representative of organic hydroperoxides arecumene hydroperoxide, paramenthane hydroperoxide, and tertiary butylhydroperoxide. Tertiary butyl hydroperoxide (t-BHP), tertiary butylperacetate (t-BPA) and “azo” initiators, such as azobisiobutyronitrile(AIBN), are preferred.

The reaction temperature is typically maintained in the range of 0° C.to 150° C. Temperatures between about 20 and 80° C. are generallypreferred. The reaction pressure is not critical. It is typically onlysufficiently high to maintain liquid phase reaction conditions; it maybe autogenic pressure, which will vary depending upon the components ofthe reaction mixture and the temperature, or it may be higher, e.g., upto 1000 psi.

In batch operations, the polymerization time of functionalized dienemonomers can be varied as desired; it may vary, for example, from a fewminutes to several days. Polymerization in batch processes may beterminated when monomer is no longer absorbed, or earlier, if desired,e.g., if the reaction mixture becomes too viscous. In continuousoperations, the polymerization mixture may be passed through a reactorof any suitable design. The polymerization reactions in such cases aresuitably adjusted by varying the residence time. Residence times varywith the type of reactor system and range, for example, from 10 to 15minutes to 24 or more hours.

The concentration of monomer in the reaction mixture may vary upwardfrom 5 percent by weight of the reaction mixture, depending on theconditions employed; the range from 20 to 80 percent by weight ispreferred.

The polymerization reactions according to this invention may be carriedout in a suitable solvent that is liquid under the conditions ofreaction and relatively inert. The solvent may have the same number ofcarbon atoms per molecule as the diene reactant or it may be in adifferent boiling range. Preferred as solvents are alkane andcycloalkane hydrocarbons. Suitable solvents are, for example, hexane,cyclohexane, methylcyclohexane, or various saturated hydrocarbonmixtures. Aromatic hydrocarbons such as benzene, toluene,isopropylbenzene, xylene, or halogenated aromatic compounds such aschlorobenzene, bromobenzene, or orthodichlorobenzene may also beemployed. Other useful solvents include tetrahydrofuran and dioxane.

Conventional emulsion recipes may also be employed with the presentinvention; however, some restrictions and modifications may arise eitherfrom the polymerizable monomer itself, or the polymerization parameters.Ionic surfactants, known in the art, including sulfonate detergents andcarboxylate, sulfate, and phosphate soaps are useful in this invention.The level of ionic surfactant is computed based upon the total weight ofthe organic components and may range from about 2 to 30 parts by weightof ionic surfactant per 100 parts by weight of organic components.

Preferably the polymerization is carried out to complete functionalizeddiene monomer conversion in order to incorporate essentially all of thepolymerizable functional group-bearing monomer. Incremental addition, ora chain transfer agent, may be used in order to avoid excessive gelformation. Such minor modifications are within the skill of the artisan.After the polymerization is complete, the polymer is recovered from aslurry or solution of the polymer. A simple filtration may be adequateto separate polymer from diluent. Other means for separating polymerfrom diluent may be employed. The polymer may be treated, separately orwhile slurried in the reaction mixture, in order to separate residues.Such treatment may be with alcohols such as methanol, ethanol, orisopropanol, with acidified alcohols, or with other similar polarliquids. In many cases the polymers are obtained in hydrocarbonsolutions and the polymer can be recovered by coagulation with acidifiedalcohol, e.g., rapidly stirred methanol or isopropanol containing 2%hydrochloric acid. Following this initial coagulation, the polymers maybe washed several more times in methanol.

The functionalized diene monomers according to the present invention mayalso be polymerized with one or more comonomers. Some adjustments in thepolymerization recipe or reaction conditions may be necessary to obtaina satisfactory rate of polymer formation, depending on the amount offunctionalized monomer included and the other monomers involved.Examples of comonomers that are useful in the practice of this inventionare diene monomers such as butadiene, isoprene, and hexadienes. One may,in addition to the diene monomers, use a vinyl monomer such as styrene,α-methylstyrene, divinyl benzene, vinyl chloride, vinyl acetate,vinylidene chloride, methyl methacrylate, ethyl acrylate, vinylpyridine,acrylonitrile, methacrylonitrile, methacrylic acid, itaconic acid andacrylic acid. Mixtures of different functionalized monomers and mixturesof different comonomers may be used. The monomer charge ratio by weightis normally from about 0.10/99.9 to 99.9/0.10 functionalized monomer tocomonomer (including any additional vinyl monomer). A charge ratio byweight of about 5/95 to about 80/20 is preferred with 10/90 to 40/60 themost preferred. According to one embodiment, the weight ratio offunctionalized diene monomer to diene monomer to vinyl monomer may rangefrom 5:75:20 to 95:5:0. Ratios will vary depending on the amount ofchemical functionality desired to be incorporated and on the reactivityratios of the monomers in the particular polymerization system used.

The functionalized monomers of this invention offer a unique ability torandomly copolymerize with conjugated diolefin monomers in solutionpolymerizations that are conducted at temperatures of 20° C. or higher.The functionalized monomers of this invention can be incorporated intovirtually any type of rubbery polymer that is capable of being made bysolution polymerization with an anionic initiator or Zeigler-Natta typeof catalyst. The polymerization employed in synthesizing the rubberypolymers will normally be carried out in a hydrocarbon solvent. Suchhydrocarbon solvents are comprised of one or more aromatic, paraffinicor cycloparaffinic compounds. These solvents will normally contain fromabout 4 to about 10 carbon atoms per molecule and will be liquid underthe conditions of the polymerization. Some representative examples ofsuitable organic solvents include pentane, isooctane, cyclohexane,methylcyclohexane, isohexane, n-heptane, n-octane, n-hexane, benzene,toluene, xylene, ethylbenzene, diethylbenzene, isobutylbenzene,petroleum ether, kerosene, petroleum spirits, petroleum naphtha, and thelike, alone or in admixture.

In the solution polymerization, there will normally be from 5 to 30weight percent monomers in the polymerization medium. Suchpolymerization media are, of course, comprised of the organic solventand monomers. In most cases, it will be preferred for the polymerizationmedium to contain from 10 to 25 weight percent monomers. It is generallymore preferred for the polymerization medium to contain 15 to 20 weightpercent monomers.

The synthetic rubbers made by the process of this invention can be madeby random copolymerization of the functionalized monomer with aconjugated diolefin monomer or by the random terpolymerization of thefunctionalized monomer with a conjugated diolefin monomer and a vinylaromatic monomer. It is, of course, also possible to make such rubberypolymers by polymerizing a mixture of conjugated diolefin monomers withone or more ethylenically unsaturated monomers, such as vinyl aromaticmonomers. The conjugated diolefin monomers which can be utilized in thesynthesis of rubbery polymers which can be coupled in accordance withthis invention generally contain from 4 to 12 carbon atoms. Thosecontaining from 4 to 8 carbon atoms are generally preferred forcommercial purposes. For similar reasons, 1,3-butadiene and isoprene arethe most commonly utilized conjugated diolefin monomers. Some additionalconjugated diolefin monomers that can be utilized include2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene,2-phenyl-1,3-butadiene, and the like, alone or in admixture.

Some representative examples of ethylenically unsaturated monomers thatcan potentially be polymerized into rubbery polymers that contain thefunctionalized monomers of this invention include alkyl acrylates, suchas methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylateand the like; vinylidene monomers having one or more terminal CH₂═CH—groups; vinyl aromatics such as styrene, α-methylstyrene, bromostyrene,chlorostyrene, fluorostyrene and the like; α-olefins such as ethylene,propylene, 1-butene and the like; vinyl halides, such as vinylbromide,chloroethane (vinylchloride), vinylfluoride, vinyliodide,1,2-dibromoethene, 1,1-dichloroethene (vinylidene chloride),1,2-dichloroethene and the like; vinyl esters, such as vinyl acetate;α,β-olefinically unsaturated nitriles, such as acrylonitrile andmethacrylonitrile; α,β-olefinically unsaturated amides, such asacrylamide, N-methyl acrylamide, N,N-dimethylacrylamide, methacrylamideand the like.

Rubbery polymers which are copolymers of one or more diene monomers withone or more other ethylenically unsaturated monomers will normallycontain from about 50 weight percent to about 99 weight percentconjugated diolefin monomers and from about 1 weight percent to about 50weight percent of the other ethylenically unsaturated monomers inaddition to the conjugated diolefin monomers. For example, copolymers ofconjugated diolefin monomers with vinylaromatic monomers, such asstyrene-butadiene rubbers which contain from 50 to 95 weight percentconjugated diolefin monomers and from 5 to 50 weight percentvinylaromatic monomers, are useful in many applications.

Vinyl aromatic monomers are probably the most important group ofethylenically unsaturated monomers which are commonly incorporated intopolydiene rubbers. Such vinyl aromatic monomers are, of course, selectedso as to be copolymerizable with the conjugated diolefin monomers beingutilized. Generally, any vinyl aromatic monomer which is known topolymerize with organolithium initiators can be used. Such vinylaromatic monomers typically contain from 8 to 20 carbon atoms. Usually,the vinyl aromatic monomer will contain from 8 to 14 carbon atoms. Themost widely used vinyl aromatic monomer is styrene. Some examples ofvinyl aromatic monomers that can be utilized include styrene,1-vinylnaphthalene, 2-vinylnaphthalene, α-methylstyrene,4-phenylstyrene, 3-methylstyrene and the like.

Some representative examples of rubbery polymers that can befunctionalized with the functionalized monomers of this inventioninclude polybutadiene, polyisoprene, styrene-butadiene rubber (SBR),α-methylstyrene-butadiene rubber, α-methylstyrene-isoprene rubber,styrene-isoprene-butadiene rubber (SIBR), styrene-isoprene rubber (SIR),isoprene-butadiene rubber (IBR), α-methylstyrene-isoprene-butadienerubber and α-methylstyrene-styrene-isoprene-butadiene rubber. In caseswhere the rubbery polymer is comprised of repeat units that are derivedfrom two or more monomers, the repeat units which are derived from thedifferent monomers, including the functionalized monomers, will normallybe distributed in an essentially random manner. The repeat units thatare derived from the monomers differ from the monomer in that a doublebond is normally consumed in by the polymerization reaction.

The rubbery polymer can be made by solution polymerization in a batchprocess by in a continuous process by continuously charging at least oneconjugated diolefin monomer, the functionalized monomer, and anyadditional monomers into a polymerization zone. The polymerization zonewill typically be a polymerization reactor or a series of polymerizationreactors. The polymerization zone will normally provide agitation tokeep the monomers, polymer, initiator, and modifier well dispersedthroughout the organic solvent the polymerization zone. Such continuouspolymerizations are typically conducted in a multiple reactor system.The rubbery polymer synthesized is continuously withdrawn from thepolymerization zone. The monomer conversion attained in thepolymerization zone will normally be at least about 85 percent. It ispreferred for the monomer conversion to be at least about 90 percent.

The polymerization will be initiated with an anionic initiator, such asan alkyl lithium compound, or a Zeigler-Natta catalyst. The alkyllithium compounds that can be used will typically contain from 1 toabout 8 carbon atoms, such as n-butyl lithium,

The amount of the lithium initiator utilized will vary with the monomersbeing polymerized and with the molecular weight that is desired for thepolymer being synthesized. However, as a general rule, from 0.01 to 1phm (parts per 100 parts by weight of monomer) of the lithium initiatorwill be utilized. In most cases, from 0.01 to 0.1 phm of the lithiuminitiator will be utilized with it being preferred to utilize 0.025 to0.07 phm of the lithium initiator.

It has been determined that it is not normally necessary to conduct thepolymerizations of this invention in the presence of a conventionalpolar modifier. The utilization of the functionalized styrene monomer,such as PES, in the polymerization eliminates the need for a polarmodifier in addition to the functionalized styrene monomer. It isaccordingly not normally necessary to conduct the polymerization in thepresence of a conventional polar modifier, such asmethyltetrahydrofurfuryl ether, ethyltetrahydrofurfuryl ether,propyltetrahydrofurfuryl ether, butyltetrahydrofurfuryl ether,hexyltetrahydrofurfuryl ether, octyltetrahydrofurfuryl ether,dodecyltetrahydrofurfuryl ether, diethyl ether, di-n-propyl ether,diisopropyl ether, di-n-butyl ether, tetrahydrofuran, dioxane, ethyleneglycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycoldimethyl ether, diethylene glycol diethyl ether, triethylene glycoldimethyl ether, trimethylamine, triethylamine,N,N,N′,N′-tetramethylethylenediamine, N-methyl morpholine, N-ethylmorpholine, or N-phenyl morpholine. The polymerizations of thisinvention that utilize functionalized styrene monomer are accordinglytypically conducted in the absence of conventional polar modifiers.

The polar modifier will typically be employed at a level wherein themolar ratio of the polar modifier to the lithium initiator is within therange of about 0.01:1 to about 5:1. The molar ratio of the polarmodifier to the lithium initiator will more typically be within therange of about 0.1:1 to about 4:1. It is generally preferred for themolar ratio of polar modifier to the lithium initiator to be within therange of about 0.25:1 to about 3:1. It is generally most preferred forthe molar ratio of polar modifier to the lithium initiator to be withinthe range of about 0.5:1 to about 3:2.

The polymerization can optionally be conducted utilizing an oligomericoxolanyl alkane as the modifier. Such oligomeric oxolanyl alkanes willtypically be of a structural formula selected from the group consistingof:

and

wherein n represents an integer from 1 to 5, wherein m represents aninteger from 3 to 5, wherein R₁, R₂, R₃, R₄, R₅, and R₆ can be the sameor different, and wherein R₁, R₂, R₃, R₄, R5, and R₆ represent a memberselected from the group consisting of hydrogen atoms and alkyl groupscontaining from 1 to about 8 carbon atoms. It is typically preferred forR₁, R₂, R₃, R₄, R₅, and R₆ represent a member selected from the groupconsisting of hydrogen atoms and alkyl groups containing from 1 to 4carbon atoms.

The polymerization temperature utilized can vary over a broad range offrom about −20° C. to about 180° C. In most cases, a polymerizationtemperature within the range of about 30° C. to about 125° C. will beutilized. It is typically preferred for the polymerization temperatureto be within the range of about 45° C. to about 100° C. It is typicallymost preferred for the polymerization temperature to be within the rangeof about 60° C. to about 90° C. The pressure used will normally besufficient to maintain a substantially liquid phase under the conditionsof the polymerization reaction.

The polymerization is conducted for a length of time sufficient topermit substantially complete polymerization of monomers. In otherwords, the polymerization is normally carried out until high conversionsof at least about 85 percent are attained. The polymerization is thenterminated by the addition of an agent, such as an alcohol, aterminating agent, or a coupling agent. For example, a tin halide and/orsilicon halide can be used as a coupling agent. The tin halide and/orthe silicon halide are continuous added in cases where asymmetricalcoupling is desired. This continuous addition of tin coupling agentand/or the silicon coupling agent is normally done in a reaction zoneseparate from the zone where the bulk of the polymerization isoccurring. The coupling agents will normally be added in a separatereaction vessel after the desired degree of conversion has beenattained. The coupling agents can be added in a hydrocarbon solution,e.g., in cyclohexane, to the polymerization admixture with suitablemixing for distribution and reaction. In other words, the coupling willtypically be added only after a high degree of conversion has alreadybeen attained. For instance, the coupling agent will normally be addedonly after a monomer conversion of greater than about 85 percent hasbeen realized. It will typically be preferred for the monomer conversionto reach at least about 90 percent before the coupling agent is added.

The tin halides used as coupling agents will normally be tintetrahalides, such as tin tetrachloride, tin tetrabromide, tintetrafluoride or tin tetraiodide. However, tin trihalides can alsooptionally be used. Polymers coupled with tin trihalides having amaximum of three arms. This is, of course, in contrast to polymerscoupled with tin tetrahalides which have a maximum of four arms. Toinduce a higher level of branching, tin tetrahalides are normallypreferred. As a general rule, tin tetrachloride is most preferred.

The silicon coupling agents that can be used will normally be silicontetrahalides, such as silicon tetrachloride, silicon tetrabromide,silicon tetrafluoride or silicon tetraiodide. However, silicontrihalides can also optionally be used. Polymers coupled with silicontrihalides having a maximum of three arms. This is, of course, incontrast to polymers coupled with silicon tetrahalides which have amaximum of four arms. To induce a higher level of branching, silicontetrahalides are normally preferred. As a general rule, silicontetrachloride is most preferred of the silicon coupling agents.

A combination of a tin halide and a silicon halide can optionally beused to couple the rubbery polymer. By using such a combination of tinand silicon coupling agents improved properties for tire rubbers, suchas lower hysteresis, can be attained. It is particularly desirable toutilize a combination of tin and silicon coupling agents in tire treadcompounds that contain both silica and carbon black. In such cases, themolar ratio of the tin halide to the silicon halide employed in couplingthe rubbery polymer will normally be within the range of 20:80 to 95:5.The molar ratio of the tin halide to the silicon halide employed incoupling the rubbery polymer will more typically be within the range of40:60 to 90:10. The molar ratio of the tin halide to the silicon halideemployed in coupling the rubbery polymer will preferably be within therange of 60:40 to 85:15. The molar ratio of the tin halide to thesilicon halide employed in coupling the rubbery polymer will mostpreferably be within the range of 65:35 to 80:20.

Broadly, and exemplary, a range of about 0.01 to 4.5 milliequivalents oftin coupling agent (tin halide and silicon halide) is employed per 100grams of the rubbery polymer. It is normally preferred to utilize about0.01 to about 1.5 milliequivalents of the coupling agent per 100 gramsof polymer to obtain the desired Mooney viscosity. The larger quantitiestend to result in production of polymers containing terminally reactivegroups or insufficient coupling. One equivalent of tin coupling agentper equivalent of lithium is considered an optimum amount for maximumbranching. For instance, if a mixture tin tetrahalide and silicontetrahalide is used as the coupling agent, one mole of the couplingagent would be utilized per four moles of live lithium ends. In caseswhere a mixture of tin trihalide and silicon trihalide is used as thecoupling agent, one mole of the coupling agent will optimally beutilized for every three moles of live lithium ends. The coupling agentcan be added in a hydrocarbon solution, e.g., in cyclohexane, to thepolymerization admixture in the reactor with suitable mixing fordistribution and reaction.

After the coupling has been completed, a tertiary chelating alkyl1,2-ethylene diamine or a metal salt of a cyclic alcohol can optionallybe added to the polymer cement to stabilize the coupled rubbery polymer.The tertiary chelating amines that can be used are normally chelatingalkyl diamines of the structural formula:

wherein n represents an integer from 1 to about 6, wherein A representsan alkylene group containing from 1 to about 6 carbon atoms and whereinR′, R″, R′″ and R″″ can be the same or different and represent alkylgroups containing from 1 to about 6 carbon atoms. The alkylene group Ais of the formula —(—CH₂—)_(m) wherein m is an integer from 1 to about6. The alkylene group will typically contain from 1 to 4 carbon atoms (mwill be 1 to 4) and will preferably contain 2 carbon atoms. In mostcases, n will be an integer from 1 to about 3 with it being preferredfor n to be 1. It is preferred for R′, R″, R′″ and R″″ to representalkyl groups which contain from 1 to 3 carbon atoms. In most cases, R′,R″, R′″ and R″″ will represent methyl groups.

In most cases, from about 0.01 phr (parts by weight per 100 parts byweight of dry rubber) to about 2 phr of the chelating alkyl 1,2-ethylenediamine or metal salt of the cyclic alcohol will be added to the polymercement to stabilize the rubbery polymer. Typically, from about 0.05 phrto about 1 phr of the chelating alkyl 1,2-ethylene diamine or metal saltof the cyclic alcohol will be added. More typically, from about 0.1 phrto about 0.6 phr of the chelating alkyl 1,2-ethylene diamine or themetal salt of the cyclic alcohol will be added to the polymer cement tostabilize the rubbery polymer.

The terminating agents that can be used to stop the polymerization andto “terminate” the living rubbery polymer include tin monohalides,silicon monohalides, N,N,N′,N′-tetradialkyldiamino-benzophenones (suchas tetramethyldiaminobenzophenone and the like),N,N-dialkylamino-benzaldehydes (such as dimethylaminobenzaldehyde andthe like), 1,3-dialkyl-2-imidazolidinones (such as1,3-dimethyl-2-imidazolidinone and the like), 1-alkyl substitutedpyrrolidinones; 1-aryl substituted pyrrolidinones,dialkyl-dicycloalkyl-carbodiimides containing from about 5 to about 20carbon atoms, and dicycloalkyl-carbodiimides containing from about 5 toabout 20 carbon atoms.

After the termination step, and optionally the stabilization step, hasbeen completed, the rubbery polymer can be recovered from the organicsolvent. The coupled rubbery polymer can be recovered from the organicsolvent and residue by means such as chemical (alcohol) coagulation,thermal desolventization, or other suitable method. For instance, it isoften desirable to precipitate the rubbery polymer from the organicsolvent by the addition of lower alcohols containing from 1 to about 4carbon atoms to the polymer solution. Suitable lower alcohols forprecipitation of the rubber from the polymer cement include methanol,ethanol, isopropyl alcohol, normal-propyl alcohol and t-butyl alcohol.The utilization of lower alcohols to precipitate the rubbery polymerfrom the polymer cement also “terminates” any remaining living polymerby inactivating lithium end groups. After the coupled rubbery polymer isrecovered from the solution, steam-stripping can be employed to reducethe level of volatile organic compounds in the coupled rubbery polymer.Additionally, the organic solvent can be removed from the rubberypolymer by drum drying, extruder drying, vacuum drying, and the like.

The polymers of the present invention can be used alone or incombination with other elastomers to prepare an rubber compounds, suchas a tire treadstock, sidewall stock or other tire component stockcompounds. In a tire of the invention, at least one such component isproduced from a vulcanizable elastomeric or rubber composition. Forexample, the rubbery polymer made by the process of this invention canbe blended with any conventionally employed treadstock rubber whichincludes natural rubber, synthetic rubber and blends thereof. Suchrubbers are well known to those skilled in the art and include syntheticpolyisoprene rubber, styrene/butadiene rubber (SBR), polybutadiene,butyl rubber, Neoprene, ethylene/propylene rubber,ethylene/propylene/diene rubber (EPDM), acrylonitrile/butadiene rubber(NBR), silicone rubber, the fluoroelastomers, ethylene acrylic rubber,ethylene vinyl acetate copolymer (EVA), epichlorohydrin rubbers,chlorinated polyethylene rubbers, chlorosulfonated polyethylene rubbers,hydrogenated nitrile rubber, tetrafluoroethylene/propylene rubber andthe like.

When the rubbery polymers made by the process of the present inventionare blended with conventional rubbers, the amounts can vary widely suchas between 10 and 99 percent by weight. In any case, tires made withsynthetic rubbers that are synthesized utilizing the technique of thisinvention exhibit decreased rolling resistance. The greatest benefitsare realized in cases where the tire tread compound is made with therubbery polymer synthesized utilizing the technique of this invention.However, benefits can also by attained in cases where at least onestructural element of the tire, such as subtread, sidewalls, body plyskim, or bead filler, is comprised of the rubbery.

The synthetic rubbers made in accordance with this invention can becompounded with carbon black in amounts ranging from about 5 to about100 phr (parts by weight per 100 parts by weight of rubber), with about5 to about 80 phr being preferred, and with about 40 to about 70 phrbeing more preferred. The carbon blacks may include any of the commonlyavailable, commercially-produced carbon blacks but those having asurface area (EMSA) of at least 20 m²/g and more preferably at least 35m²/g up to 200 m²/g or higher are preferred. Surface area values used inthis application are those determined by ASTM test D-1765 using thecetyltrimethyl-ammonium bromide (CTAB) technique. Among the usefulcarbon blacks are furnace black, channel blacks and lamp blacks. Morespecifically, examples of the carbon blacks include super abrasionfurnace (SAF) blacks, high abrasion furnace (HAF) blacks, fast extrusionfurnace (FEF) blacks, fine furnace (FF) blacks, intermediate superabrasion furnace (ISAF) blacks, semi-reinforcing furnace (SRF) blacks,medium processing channel blacks, hard processing channel blacks andconducting channel blacks. Other carbon blacks which may be utilizedinclude acetylene blacks. Mixtures of two or more of the above blackscan be used in preparing the carbon black products of the invention.Typical values for surface areas of usable carbon blacks are summarizedin the following table.

Carbon Black ASTM Designation (D-1765-82a) Surface Area (D-3765) N-110126 m²/g N-220 111 m²/g N-330  83 m²/g N-339  95 m²/g N-550  42 m²/gN-660  35 m²/g

The carbon blacks utilized in the preparation of rubber compounds may bein pelletized form or an unpelletized flocculent mass. Preferably, formore uniform mixing, unpelletized carbon black is preferred. Thereinforced rubber compounds can be cured in a conventional manner withabout 0.5 to about 4 phr of known vulcanizing agents. For example,sulfur or peroxide-based curing systems may be employed. For a generaldisclosure of suitable vulcanizing agents one can refer to Kirk-Othmer,Encyclopedia of Chemical Technology, 3rd ed., Wiley Interscience, N.Y.1982, Vol. 20, pp. 365-468, particularly “Vulcanization Agents andAuxiliary Materials” pp. 390-402. Vulcanizing agents can, of curse, beused alone or in combination. Vulcanizable elastomeric or rubbercompositions can be prepared by compounding or mixing the polymersthereof with carbon black and other conventional rubber additives suchas fillers, plasticizers, antioxidants, curing agents and the like,using standard rubber mixing equipment and procedures and conventionalamounts of such additives.

The functionalized styrene monomer can be synthesized by (1) reacting asecondary amine with an organolithium compound to produce a lithiumamide, and (2) reacting the lithium amide with divinylbenzene ordiisopropenyl benzene to produce the functionalized styrene monomer.This procedure can be depicted as follows:

A process for synthesizing an amino ethyl styrene monomer whichcomprises: (1) reacting divinyl benzene with a cyclic amine in areacting mixture in the presence of an alkyl lithium compound at atemperature which is within the range of −80° C. to 80° C. to producethe amino ethyl styrene; and (2) deactivating the alkyl lithium compoundby adding an alcohol or water to the reaction mixture containing theamino ethyl styrene.

Functionalized monomers that contain cyclic amines can also be made bythe same reaction scheme wherein a cyclic secondary amine is employed inthe first step of the reaction. This reaction scheme can be depicted asfollows:

In another embodiment of this invention a functionalized monomer can besynthesized by a process that comprises (1) reacting a secondary aminewith a 2,3-dihalopropene to produce a vinyl halide containing secondaryamine having a structural formula selected from the group consisting of

wherein R and R′ can be the same or different and represent allyl,alkoxyl or alkyl groups containing from 1 to about 10 carbon atoms, andwherein X represents a halogen atom, and

wherein m represents an integer from 4 to about 10, and wherein Xrepresents a halogen atom; and (2) reacting the vinyl halide containingsecondary amine with a vinyl magnesium halide to produce the monomer,wherein the monomer has a structural formula selected from the groupconsisting of

wherein R and R′ can be the same or different and represent allyl,alkoxyl or alkyl groups containing from 1 to about 10 carbon atoms, and

wherein m represents an integer from about 4 to about 10. Such areaction scheme can be depicted as follows:

In the first step of this reaction scheme a secondary cyclic amine isreacted with a 2,3-dihalopropene (2,3-bromopropene is shown above). Thisstep is typically conducted in an organic solvent, such as diethylether, at a temperature which is within the range of about −20° C. toabout 60° C., and is preferable conducted at a temperature which iswithin the range of 0° C. to about 30° C. As can be seen this results inthe production of a vinyl halide containing secondary amine.

In the second step of the process the vinyl halide containing secondaryamine is reacted with a vinyl magnesium halide to produce thefunctionalized monomer. The second step is conducted in a polar organicsolvent, such as tetrahydrofuran or diethyl ether. The second step isalso conducted at a temperature that is within the range of about −20°C. to about 60° C., and is preferable conducted at a temperature whichis within the range of 0° C. to about 30° C.

This invention is illustrated by the following examples that are merelyfor the purpose of illustration and are not to be regarded as limitingthe scope of the invention or the manner in which it can be practiced.Unless specifically indicated otherwise, parts and percentages are givenby weight.

EXAMPLE 1

In this experiment 2-(N-hexamethyleneimino)-methyl 1,3-butadiene wassynthesized utilizing the technique of this invention. In the procedureused a solution of 2,3-dibromopropane (0.1 mol) in ethyl ether wasslowly added to a solution of hexamethyleneimine (0.4 mol) in ethylether at 0° C. The reaction mixture was stirred overnight at roomtemperature. The next day a 1M NaOH solution was added to quench themixture and the organic layer was collected using a separatory funneland extracted with diethyl ether. The organic layer was subsequentlywashed with water two times. After drying with sodium sulfate, thefiltrate was evaporated and the resulting residue was distilled to yield2-bromo-3-(N-hexamethyleneimino)propene. The boiling point and yield ofthe product were determined to be 65-68° C. at 30 mm-Hg. The yield wasdetermined to be 60%. The molecular structure of2-bromo-3-(N-hexamethylene-imino)propene was verified by proton NMR.

Vinyl magnesium bromide in tetrahydrofuran (THF; 0.085 mol) was addeddropwise to a flask containing the2-bromo-3-(N-hexamethylene-imino)propene (0.056 mol) in the presence of[1,3-bis(diphenylphosphino)propane] dichloronickel(II) (0.21 mol) at 0°C. After stirring for 24 hours at room temperature, the hydrolysis ofthe reaction mixture by saturated ammonium chloride solution was carriedout and followed by extraction with diethyl ethyl three times. Theorganic material was dried by sodium sulfate and then filtered. Afterevaporating the solvent, the residue was distilled to give a colorlessliquid of 2-(N-hexa-methyleneimino)-methyl 1,3-butadiene. The boilingpoint and yield were −114° C. at 30 mm-Hg and 60%, respectively. Themolecular structure of the resulting product was verified by proton NMR.

EXAMPLE 2

The preparation of 2-(N,N-diethylamino)-methyl-1,3-butadiene isdescribed in this example. The procedure described in Example 1 wasutilized except that N,N-diethylamine was used in place ofhexamethyleneimine. The yield for the intermediate product,2-bromo-3-(N,N-diethylamino)propene was 98%. The boiling point and yieldof the final product, 2-(N,N-diethylamino)-methyl-1,3-butadine wasdetermined to be 112-114° C. at 30 mm-Hg and 50%, respectively.

EXAMPLES 3-5

In these experiments 2-(N-pyrrolidino)-methyl-1,3-butadiene,2-(N-morpholino)-methyl-1,3-butadiene, and2-(N-piperidino)-methyl-1,3-butadiene were synthesized utilizing aprocedure that is similar to the one described in Example 1 except thatpyrrolidine, morpholine and piperidine were used in place of thehexamethyleneimine.

EXAMPLE 6

In this experiment, a 25/75 SBR containing 1% of hexamethyleneimine(HMI) functional groups was prepared. 2350 g of asilica/alumina/molecular sieve dried premix containing 19.50 weightpercent styrene and 1,3-butadiene in hexanes was charged into aone-gallon (3.8 liters) reactor. The styrene to 1,3-butadiene ratio was25:75. 4.6 grams of a neat 2-(N-hexamethyleneimino)-methyl 1,3-butadienewas added to the reactor. Then, 2.9 ml of 1 M solution ofN,N,N′,N′-tetramethyethylenediamine (TMEDA) and 2.3 ml of 1.6 M n-butyllithium (n-BuLi) in hexanes were added to the reactor, respectively. Thepolymerization was carried out at 70° C. for 90 minutes. The GC analysisof the residual monomer contained in the polymerization mixtureindicated that the all monomers were consumed at this time, the polymercement was then shortstopped with ethanol and then removed from thereactor and stabilized with 1 phm of antioxidant. After evaporatinghexanes, the resulting polymer was dried in a vacuum oven at 50° C.

The styrene-butadiene rubber (SBR) produced was determined to have aglass transition temperature (Tg) at −33° C. It was also determined tohave a microstructure which contained 41 percent 1,2-polybutadieneunits, 34 percent 1,4-polybutadiene units and 25 percent randompolystyrene units. It also contained about 1 weight percent of HMIunits. The Mooney viscosity (ML-4) at 100° C. for this SBR wasdetermined to be 27. The GPC data of this polymer was also determined tohave a Mn of 129,000 and Mw of 136,000. The polydispersity (Mw/Mn) was1.05. The HMI functionality of the resulting SBR was verified via aHPLC-GPEC (Gradient polymer elution chromatography) method using NovapakC18 column using a mixture of acetonitrile/THF as solvent. As determinedby GPEC method, 93% of this polymer contains HMI functional groups.

EXAMPLES 7-8

In these examples, 25/75 SBRs containing 0.25 and 0.5 weight percent of2-(N-hexamethyleneimino)-methyl 1,3-butadiene were prepared using theprocedures described in Example 6 except that 1.2 and 2.3 grams of2-(N-hexamethyleneimino)-methyl 1,3-butadiene, respectively were addedto the premix prior to polymerization. The characterization data ofthese two polymers are listed in Table 1.

EXAMPLE 9

In the example, a tin coupled 25/75 SBR containing 0.5 weight percent of2-(N-hexamethyleneimino)-methyl 1,3-butadiene was prepared. 2350 g of asilica/alumina/molecular sieve dried premix containing 19.50 weightpercent styrene and 1,3-butadiene in hexanes was charged into aone-gallon (3.8 liters) reactor. The styrene to 1,3-butadiene ratio was25:75. 2.3 grams of a neat 2-(N-hexamethyleneimino)-methyl 1,3-butadienewas added to the reactor. 2.9 ml of 1 M solution ofN,N,N′,N′-tetramethyethylenediamine (TMEDA) and 2.3 ml of 1.6 M n-butyllithium (n-BuLi) in hexanes were added to the reactor, respectively. Thepolymerization was carried out at 70° C. for 90 minutes. The GC analysisof the residual monomer contained in the polymerization mixtureindicated that the all monomers were consumed at this time. 0.9 ml of a1 M solution of tin tetrachloride in hexanes was then added to thepolymerization mixture. The coupling reaction was allowed to proceed at70° C. for 30 minutes. The coupling efficiency was 69%. Thecharacterization data of this coupled and HMI functionalized polymer arealso listed in Table 1.

COMPARATIVE EXAMPLE 10

In this example, a control 25/75 SBR containing 0 weight percent of2-(N-hexamethyleneimino)-methyl 1,3-butadiene was prepared using theprocedures described in Example 6 except no2-(N-hexamethyleneimino)-methyl 1,3-butadiene was used. Thecharacterization data of this polymer are also included in Table 1.

TABLE 1 wt % HMI- GPC Example No. Monomer Coupler Tg (° C.) ML-4 Mn MwMw/Mn 10 0 None −33 23 137,000 139,000 1.02 7 0.25 None −36 21 126,000128,000 1.01 8 0.50 None −32 27 139,000 142,000 1.03 6 1.00 None −33 27129,000 136,000 1.05 9 0.50 SnCl4 −32 83 677,000 812,000 1.20 (42%)329,000 335,000 1.02 (27%) 145,000 155,000 1.06 (31%)

EXAMPLE 11

In this example, a 25/75 SBR containing 0.5 weight percent of2-(N-hexamethyleneimino)-methyl 1,3-butadiene was prepared using theprocedures described in Example 6 except that 2.3 grams of2-(N-hexamethyleneimino)-methyl 1,3-butadiene was pre-reacted withn-BuLi in the presence of TMEDA. The pre-reacted n-BuLi containing HMIfunctional groups was then used as the catalyst to initiate thepolymerization. The characterization data of this polymer are listed inTable 2.

EXAMPLES 12-13

In these examples, 25/75 SBRs containing 0.1 and 0.25% weight percent of2-(N-hexamethyleneimino)-methyl 1,3-butadiene were prepared using theprocedures described in Example 11 except that 0.5 and 1.2 grams of2-(N-hexamethyleneimino)-methyl 1,3-butadiene were pre-reacted withn-BuLi in the presence of TMEDA. The characterization data of thispolymer are listed in Table 2.

EXAMPLE 14

In this example, a 25/75 SBR containing 0.5 weight percent of2-(N-hexamethyleneimino)-methyl 1,3-butadiene were prepared using theprocedures described in Example 6 except that 4.6 grams of2-(N-hexamethyleneimino)-methyl 1,3-butadiene was diluted with 10.8 mlof dried hexane and added sequentially in 5 equal portions (3 ml each)to the polymerization mixture at 0, 5, 15, 30 and 90 minutes timeperiods. The total polymerization time was 100 minutes. Thecharacterization data of this polymer are listed in Table 2.

EXAMPLES 15-16

In these examples, 25/75 SBRs containing 0.1 and 0.25 weight percent of2-(N-hexamethyleneimino)-methyl 1,3-butadiene were prepared using theprocedures described in Example 14 except that 0.5 and 1.2 grams of2-(N-hexamethyleneimino)-methyl 1,3-butadiene were added sequentially tothe polymerization mixture as indicated in Example 14. Thecharacterization data of this polymer are listed in Table 2.

EXAMPLE 17

In this example, a 25/75 SBR containing 0.25 weight percent of2-(N-hexamethyleneimino)-methyl 1,3-butadiene was prepared using theprocedures described in Example 6 except that 1.2 grams of2-(N-hexamethyleneimino)-methyl 1,3-butadiene was added to thepolymerization mixture at the end of polymerization (90 minutes). Thepolymerization was continued for another 30 minutes at 70° C. Thecharacterization data of this polymer are listed in Table 2.

TABLE 2 wt % HMI- Mode of HMI- GPC Example No. Monomer Monomer additionTg (° C.) ML-4 Mn Mw Mw/Mn 7 0.25 initial charge −36 21 126,000 128,0001.01 8 0.50 initial charge −32 27 139,000 142,000 1.03 6 1.00 initialcharge −33 27 129,000 136,000 1.05 11 0.50 pre-reacted −33 27 133,900136,300 1.02 12 0.10 pre-reacted −33 26 136,600 138,800 1.02 13 0.25pre-reacted −37 24 129,000 136,000 1.02 14 0.50 sequential −36 21 81,60086,730 1.06 (50%) 212,000 235,600 1.11 (50%) 15 0.10 sequential −35 25115,900 121,300 1.05 (80%) 257,600 265,200 1.03 (20%) 16 0.25 sequential−33 24 95,800 100,000 1.04 (57%) 227,000 245,200 1.08 (43%) 17 0.25 endcharge −33 29 138,400 140,200 1.01

COMPARATIVE EXAMPLE 18

In this example, a 25/75 SBR containing 2% of pyrrolidine functionalgroups was prepared via copolymerizing styrene/1,3-butadiene monomerswith 4-(N-pyrrolidinomethyl) styrene. The procedure described in example6 was employed except that 9.2 grams of a neat 4-(N-pyrrolidinomethyl)styrene was used instead of 2-(N-hexamethyleneimino)-methyl1,3-butadiene. Based on GC analysis of the residual monomer, thepolymerization was also completed in 90 minutes at 70° C. The GC dataalso indicated that 4-(N-pyrrolidinomethyl) styrene was randomlydistributed along the polymer chains.

The styrene-butadiene rubber (SBR) produced was determined to have aglass transition temperature (Tg) at −30° C. It was also determined tohave a microstructure which contained 42 percent 1,2-polybutadieneunits, 32 percent 1,4-polybutadiene units, 24 percent random polystyreneunits and 2% 4-(N-pyrrolidino-methyl) styrene units. The Mooneyviscosity (ML-4) at 100° C. for this SBR was determined to be 27. TheGPC data of this polymer was also determined to have a Mn of 131,000 andMw of 134,000. The polydispersity (Mw/Mn) was 1.02

COMPARATIVE EXAMPLES 19-20

In these examples, 25/75 SBRs containing 2 weight percent of HMI andpiperidine functional groups were prepared using the proceduresdescribed in Example 18 except that 4-(N-hexamethyleneiminomethyl)styrene and 4-(N-piperidinomethyl) styrene, in place of4-(N-pyrrolidinomethyl) styrene, were added to the premix, respectivelyprior to polymerization. The Tg and ML-4 of these two aminefunctionalized SBRs were −30° C., 26 and −31° C., 28, respectively.

EXAMPLE 21

In this example, a 25/75 SBRs containing 1 weight percent ofdi-allylamine functional groups was prepared using the proceduresdescribed in Example 18 except that 4-(N-diallylaminomethyl) styrene wasused instead of 4-(N-pyrrolidinomethyl) styrene. The polymer wasdetermined to have a Tg at −40° C.

EXAMPLE 22

In this experiment, a high trans 10/90 SBR containing 0.5% pyrrolidinefunctional groups was prepared. 2150 g of a silica/alumina/molecularsieve dried premix containing 19.50 weight percent styrene/1,3-butadienein hexane was charged into a one-gallon (3.8 liters) reactor. 2.1 gramsof 2-(N-hexamethylene-imino)-methyl 1,3-butadiene was also added to thereactor. 20 ml of a 0.172 M pre-alkylated barium catalyst (prepared byreacting one mole of barium salt of di(ethylene glycol)ethylether(BaDEGEE) in ethylbenzene with 4 moles tri-n-octylaluminum (TOA) inhexanes at 70° C.) and 7 ml of 1.6 M solution of n-butyllithium (n-BuLi)in hexanes were added to the reactor The polymerization was carried outat 100° C. for 3 hours. The GC analysis of the residual monomercontained in the polymerization mixture indicated that the total monomerconversions 96% and disappearance of 2-(N-hexamethyleneimino)-methyl1,3-butadiene monomer. One ml of neat ethanol was added to shortstop thepolymerization. The polymer cement was then removed from the reactor andstabilized with 1 phm of antioxidant. After evaporating hexanes, theresulting polymer was dried in a vacuum oven at 50° C.

The HTSBR produced was determined to have a glass transition temperature(Tg) at −83° C. and a melting temperature, Tm at 17° C. It was thendetermined to have a microstructure which contained 3.5 percent1,2-polybutadiene units, 14.4 percent cis-1,4-polybutadiene units 74.5%trans-1,4-polybutadiene units and 7.6% polystyrene. Both NMR and GPECindicated the presence of HMI functional groups.

The Mooney viscosity (ML-4) at 100° C. for this polymer was determinedto be 98. The GPC measurements indicated that the polymer has a numberaverage molecular weight (Mn) of 107,5000 and a weight average molecularweight (Mw) of 187,30,000. The polydispersity (Mw/Mn) of the resultingpolymer is 1.74.

EXAMPLES 23-24

In these examples, high trans polybutadiene and SBR containing 1.0weight percent of pyrrolidine functional groups were prepared by using4-(N-pyrrolidinomethyl)styrene as a comonomer. The procedures describedin Example 22 were used in these examples except that 1,3-butadiene wasused as the main monomer in Example 23. And,4-(N-pyrrolidinomethyl)styrene was used instead of2-(N-hexamethylene-imino)-methyl 1,3-butadiene. The polymerization wasconducted at 70° C. for 4 hours. The polymer characterization data ofthese polymers are listed in Table 3.

TABLE 3 GPC Example No Polymer % pyrrolidine Tg (° C.) Tm (° C.) Mn MwMw/Mn 23 HTPBD 1.0 −90 35, 45, 59 83,400 100,500 1.21 24 HTSBR 1.0 −8427, 39 69,540 81,300 1.17

EXAMPLE 25

In this example, a cis-1,4-polybutadiene containing 0.5 weight percentof 2-(N-hexamethyleneimino)-methyl 1,3-butadiene was prepared in abottle using a catalyst consisting of neodymiumneodecanoate/tri-n-octylaluminum/t-butylchloride, at a 1/10/2 molarratio, at 70° C. for 1 hours. GC analysis of residual monomer showed thepolymerization was completed. 2-(N-hexamethyleneimino)-methyl1,3-butadiene also was consumed. The polybutadiene produced wasdetermined to have a glass transition temperature (Tg) at −110° C. and amelting peak at −6° C. It was also determined to have a microstructurewhich contained 0.7 percent 1,2-polybutadiene units, 99.3 percent1,4-polybutadiene units. The polymer was also determined to have a Mn of324,000 and a Mw of 815,000. The polydispersity (Mw/Mn) was 2.51. Thepresence of HMI functional groups was also verified by GPEC method.

EXAMPLE 26

In this example, a cis-1,4-polyisoprene containing 0.5 weight percent of2-(N-hexamethyleneimino)-methyl 1,3-butadiene was prepared in a bottleusing a catalyst consisting of neodymiumneodecanoate/tri-n-octylaluminum/t-butylchloride, at a 1/10/2 molarratio, at 70° C. for 2 hours. GC analysis of residual monomer showed thepolymerization was completed. 2-(N-hexamethyleneimino)-methyl1,3-butadiene also was consumed. The polyisoprene produced wasdetermined to have a glass transition temperature (Tg) at −67° C. Thepolymer was also determined to have a Mn of 497,000 and a Mw of1,207,000. The polydispersity (Mw/Mn) was 2.42. The presence of HMIfunctional groups was also verified by NMR and GPEC techniques.

COMPARATIVE EXAMPLE 27

One mole of neat piperidine was added under nitrogen to a round bottomflask containing 500 ml of 20-35% aqueous sodium hydroxide. The roundbottom flask was equipped with a mechanical stirrer. The mixture wasthen cooled to 40° F. and one mole of 4-vinyl benzyl chloride or amixture of 3-vinyl benzyl chloride and 4-vinyl benzyl chloride was addeddrop-by-drop to the mixture for a period of 30-60 minutes at atemperature of 40° F. to 50° F. Upon completion of the addition, thereaction mixture was heated to room temperature with the stirring beingcontinued for a period of 2 to 4 hours. The reaction mixture was thenextracted with toluene or diethyl ether. The organic filtrate was thendried over potassium hydroxide (KOH) pellets.

The toluene or diethyl ether was then removed from the dried filtrateusing a rotary evaporator under reduced pressure. The neatpyrrolidinomethyl styrene was then recovered by vacuum distillation. Theboiling points of the mixture of 3-N-piperidinomethyl styrene and4-N-piperidinomethyl styrene was 115-120° C. at 0.5 mm-Hg. The yield wasabout 70 percent.

By utilizing a similar procedure 4-N-hexamethylene iminomethyl styrene,4-N-pyrrolidino methyl styrene, and 4-N-dialkyl amino styrene ormixtures of 3-isomers and 4-isomers can be prepared.

COMPARATIVE EXAMPLES 28-32

In this series of experiments the rubber samples made in Examples 6-10were compounded with 55 phr (parts by weight per 100 parts by weight ofrubber) of carbon black and cured. The physical properties of thecompounded rubber samples are shown Table 4.

TABLE 4 Percent Uncured G′ Rubber from Functionalized (15% @ 0.83 CuredG′ Cured tan delta Example Example No. Monomer Hz) (5% @ 1 Hz) (5% @ 1Hz) 28 10 0.0 142 kPa 2.0 MPa 0.178 29 7 0.25 192 kPa 1.6 MPa 0.113 30 80.50 242 kPa 1.8 MPa 0.122 31 6 1.0 281 kPa 1.5 MPa 0.119 32 9 0.5* 405kPa 1.6 MPa 0.097 *The rubber was also coupled with tin tetrachloride(SnCl₄).

This series of experiments shows that the solution elastomercompositions with functionalized monomers exhibited increased uncuredviscosity (G′ at 15% strain) indicating the presence of stronginteractions between polymer and filler. The composition with functionalcomonomer also showed significantly reduced tan delta values indicatingthat improved rolling resistance would be realized if the rubber wasused in tire tread compounds.

EXAMPLE 33

In this experiment 3-(2-pyrrolidinoethyl) and 4-(2-pyrrolidinoethyl)styrene were syntnesized. In the procedure used 1030 grams of 80%divinylbenzene (824 grams of pure divinylbezene 6.324 moles; the ratioof meta-DVB to para-DVB was normally 60:40) was added under nitrogen toa 5 litter flask equipped with a stirrer that contained 2 liters of dryhexane. To this homogenous solution was added 6.239 moles (450 g or 528ml of dry prrolidine). This homogenous solution was cooled with wet/iceacetone to −5° C. At this temperature, 2.5% of the 6329 mmoles which is155.9 mmoles of n-butyllithium was added all at once. The reactiontemperatures rose to +55° C. The reaction was allowed to cool to +5° C.for one hour. After that the reaction was neutralized with distilledwater and three samples were taken for gas chromatography (GC) analysis.

After drying the reaction mixture with magnesium sulfate, the hexane inthe filtrate was evaporated and the resulting residue was distilled atreduced pressure to yield a mixture of 3 and4-(2-pyrrolidinoethyl)styrene. The boiling point was 105-110° C. at 0.3mm-Hg. The product contained 96% of a mixture of 3-(2-pyrrolidinoethyl)styrene and 4-(2-pyrrolidinoethyl) styrene and 4% of a mixture of3-(2-pyrrolidinoethyl) styrene and 4-(2-pyrrolidinoethyl)-1-ethylbenzeneas determined by proton NMR in CDCl3. The ratio of3-(2-pyrrolidinoethyl)styrene to 4-(2-pyrrolidinoethyl)styrene wasnormally 60:40.

EXAMPLE 34

In this experiment, a 2/18/80pyrrolidinoethylstyrene/styrene/1,3-butadiene terpolymer was prepared.In the procedure used, 2068 grams of a silica/alumina/molecular sievedried premix containing 20.14 weight percent of pyrrolidinoethylstyrene, styrene and 1,3-butadiene in hexane was charged into aone-gallon (3.8 liters) reactor. The pyrrolidinoethylstyrene (PES) usedcontained a mixture of 3-(2-pyrrolidinoethyl) styrene and4-(2-pyrrolidinoethyl) styrene and a small amount of mixed3-(2-pyrrolidinoethyl)-1-ethylbenzene and4-(2-pyrrolidinoethyl)-1-ethylbenzene. The ratio of3-(2-pyrrolidinoethyl)styrene to 4-(2-pyrrolidinoethyl)styrene could bevaried, although it was normally 60:40. The ratio of PES to styrene to1,3-butadiene ratio was 2:18:80. Then, 0.48 ml of neatN,N,N′,N′-tetramethylethylenediamine (TMEDA) and 1.5 ml of 1.6 M n-butyllithium (n-BuLi) in hexanes solvent were added to the reactor. The molarratio of TMEDA to n-BuLi was 1.5:1. The polymerization was carried outat a temperature of 70° C. for 90 minutes. A GC analysis of the residualmonomer contained in the polymerization mixture indicated that the allmonomers had been consumed by this time. The polymer cement was thenshortstopped with ethanol and removed from the reactor and stabilizedwith 1 phm of antioxidant. After evaporating hexane, the resultingpolymer was dried in a vacuum oven at 50° C. The GC analysis of theresidual monomer with respect to the polymerization time also indicatedthat PES was randomly distributed along the polymer chain.

The PES-styrene-butadiene terpolymer produced was determined to have aglass transition temperature (Tg) at −34° C. It was also determined tohave a microstructure which contained 48.0 percent 1,2-polybutadieneunits, 32.9 percent 1,4-polybutadiene units, 17.4 percent randompolystyrene units and 1.7 percent of PES units. The Mooney viscosity(ML-4) at 100° C. for this polymer was determined to be 42. The GPC dataof this polymer was also determined to have a number average molecularweight (Mn) of 181,900 and weight average molecular weight (Mw) of190,700. The polydispersity (Mw/Mn) of the polymer was 1.05.

Other PES-styrene-butadiene terpolymers containing 0.25, 0.5, 1.0 and5.0 weight percent PES having similar glass transition temperatureswithin the range of −32° C. to −37° C. were prepared similarly forcompound evaluation.

COMPARATIVE EXAMPLE 35

In this example, a 2/18/80pyrrolidinomethylstyrene/styrene/1,3-butadiene terpolymer was preparedusing the procedures described in Example 34 except thatpyrrolidinomethyl styrene (PMS) was used instead of PES. The PMS wasprepared from vinylbenzylchloride and normally was a mixture3-pyrrolidino methyl) styrene and 4-(pyrrolidino methyl) styrene. Themolar ratio of 3-(pyrrolidinomethyl) styrene to 4-(pyrrolidino methyl)styrene was normally closed to 60:40. Also, 0.55 ml of a neat TMEDA and2.1 ml of 1.6 M n-BuLi were used as the initiator.

The PMS-styrene-butadiene terpolymer produced was determined to have aglass transition temperature (Tg) at −34° C. The Mooney viscosity (ML-4)at 100° C. for this polymer was determined to be 37. The GPC data ofthis polymer was also determined to have a Mn of 147,100 and Mw of180,600. The polydispersity (Mw/Mn) was 1.23. The polydispersity of thispolymer is significantly higher than that of PES-styrene-butadieneterpolymer obtained in Example 1 (1.23 vs. 1.05), indicating sidereactions might occur when PMS was used as a co-monomer.

EXAMPLE 36

In this experiment, a tin coupled 1/19/80pyrrolidinoethylstyrene/styrene/1,3-butadiene terpolymer was prepared. Atotal of 2006 grams of a silica/alumina/molecular sieve dried premixcontaining 20.4 weight percent of pyrrolidinoethyl styrene (PES),styrene and 1,3-butadiene in hexane was charged into a one-gallon (3.8liters) reactor. The PES to styrene to 1,3-butadiene ratio was 1:19:80.Then, 0.52 ml of neat N,N,N′,N′-tetramethylethylenediamine (TMEDA) and2.0 ml of 1.6 M n-butyl lithium (n-BuLi) in hexane were added to thereactor, respectively. The polymerization was carried out at 70° C. for90 minutes. The GC analysis of the residual monomer contained in thepolymerization mixture indicated that all of the monomer had beenconsumed by that time. Then, 250 grams of the polymer cement was removedfrom the reactor and stabilized with 1 phm of antioxidant. Then, 1.30 mlof a 1 M tin tetrachloride solution in hexane was added to the remainingcement in the reactor. The molar ratio of tin tetrachloride to n-BuLiwas 0.5:1. The coupling reaction was conducted at 70° C. for 30 minutes.The polymer cement was then removed from the reactor and stabilized with1 phm of antioxidant. After evaporating the hexane solvent, theresulting polymer was dried in a vacuum oven at 50° C.

The PES-styrene-butadiene terpolymer produced was determined to have aglass transition temperature (Tg) at −35° C. The Mooney viscosity (ML-4)at 100° C. for this polymer was determined to be 81. The Mooney ML-4viscosity of the base polymer was also determined to be 16. The GPC dataindicated that the coupling efficiency was 75%.

EXAMPLES 37-40

In these examples, tin coupled PES-styrene-butadiene terpolymerscontaining 0.25, 0.5, 2.0 and 5.0% PES were prepared using theprocedures described in Example 3 except that the amount of PES waschanged from 1.0% to 0.25, 0.5, 2.0 and 5.0%. The molar ratio of tintetrachloride to n-BuLi was kept the same (0.5:1). The Tg, Mooneyviscosity and the percent coupling of these polymers are listed in Table5.

TABLE 5 ML-4 Example % PES Tg (° C.) Base Coupled % Coupling 37 0.25 −3625 106 80 38 0.50 −39 19 95 77 36 1.00 −35 16 81 75 39 2.00 −35 17 65 —40 5.00 −37 16 81 —

EXAMPLE 41

In this example, a silicone coupled PES-styrene-butadiene terpolymercontaining 2.0% PES was prepared using the procedures described inExample 36 except that the amount of PES was changed from 1.0% to 2.0%and silicon tetrachloride was used as the coupling agent. The molarratio of silicon tetrachloride to n-BuLi was kept the same (0.5:1). Thepolymer was determined to have a glass transition temperature (Tg) at−36° C. The Mooney viscosity of base and silicon coupled polymers were17 and 86, respectively.

EXAMPLES 42-43

In these examples, coupled PES-styrene-butadiene terpolymers containing1.0% PES were prepared using the procedures described in Example 36except that the silicon tetrachloride, and a mixture containing 50% tintetrachloride and 50% silicon tetrachloride were used as coupling agentsThe molar ratio of coupling agent to n-BuLi was kept the same (0.5:1).The glass transition temperature (Tg), Mooney viscosity, and the percentof coupling agent used are listed in Table 6.

TABLE 6 Coupling ML-4 Example % PES agent Tg (° C.) Base Coupled %Coupling 42 1.00 SiCl4 −32 21 97 81 43 1.00 50/50 SiCl4/SnCl4 −33 21 8975

EXAMPLES 44-45

In these examples, tin coupled PES-styrene-butadiene terpolymerscontaining 1.0% PES were prepared using the procedures described inExample 36 except that the molar ratio of tin tetrachloride to n-BuLiwas changed from 0.5:1 to 0.25:1 and 0.375:1, respectively. The Tg,Mooney viscosity and the percent coupling of these polymers are listedin Table 7.

TABLE 7 SnCl4/ % n-BuLi ML-4 Example PES ratio Tg (° C.) Base Coupled %Coupling 44 1.00 0.25:1 −36 13 81 81 45 1.00 0.375:1  −37 12 77 77 361.00 0.50:1 −35 16 81 75

COMPARATIVE EXAMPLES 46

In this example, tin coupled PMS-styrene-butadiene terpolymer containing1.0% PMS was prepared using the procedures described in Example 36except that the molar ratio of tin tetrachloride to n-BuLi was changedfrom 0.5:1 to 0.25:1. The Tg, Mooney viscosity and the percent couplingof this polymer are listed in Table 8. As shown in Table 8, a PESfunctionalized polymer can be more effectively coupled with tintetrachloride than the PMS functionalized polymer. Polymers with bettertin coupling normally provide better compound properties.

TABLE 8 % Functional SnCl₄/n-BuLi ML-4 Example monomer ratio Tg (° C.)Base Coupled % Coupling 46 1% PMS 0.25:1 −33 18 65 62 44 1% PES 0.25:1−36 13 81 81

EXAMPLE 47

In this example, a 1/11/88 PES/styrene/1,3-butadiene terpolymer wasprepared using the procedure described in Example 34 except that theratio of PES to styrene and to 1,3-butadiene was changed to 1:11:80 andthe molar ratio of TMEDA to n-BuLi was also changed to 1:1. GC analysisof residual monomer with respect to polymerization time indicated thatPES was randomly distributed along the polymer chain. The resultingterpolymer had a Tg at −42° C. and was determined to a have a ML-4 of47.

EXAMPLE 48

In this example, a 1/99 PES/isoprene copolymer was prepared using theprocedure described in Example 34 except that a mixture of PES andisoprene in hexane was used as the monomer premix and DTP(2,2-di-tetrahydrofuryl propane) was used as the modifier. The molarratio of DTP to n-BuLi was 2.5:1. GC analysis of residual monomerindicated that the polymerization was completed in an hour. Theresulting copolymer had a Tg at −14° C. and was determined to a have aML-4 of 82.

EXAMPLES 49-65

In this series of experiments tire tread compounds that were loaded withcarbon black as a filler were make with styrene-butadiene rubber thathad various amounts of a mixture of 3-(2-pyrrolidinomethyl)styrene and4-(2-pyrrolidinomethyl)styrene (PMS) incorporated therein. The amount offunctionalized styrene monomer that was incorporated into thestyrene-butadiene rubber is shown in Table 9. These tire treadcompositions were made by mixing 55 phr (parts by weight per 100 partsby weight of rubber) of N299 carbon black, 10 phr of processing oil, 3phr of zinc oxide, 2 phr of stearic acid, 1.5 phr of antioxidant, 1.2phr of sulfenamide accelerator, and 1.4 phr of sulfur into variousstyrene-butadiene rubbers having different contents of boundfunctionalized styrene monomer. The characterization of the tire treadcompounds made are shown in Table 9 (G′ was measure on uncured compoundsand tan delta was measured on cured samples at 60° C.).

TABLE 9 Example PMS Macrostructure ML-4* G′ (kPa) Tan delta 49   0%linear 41 500 0.177 50   0% linear 63 595 0.170 51 0.25% linear 65 5840.149 52 0.25% linear 66 606 0.135 53  0.5% linear 27 499 0.165 54  0.5%linear 27 500 0.145 55  0.5% linear 32 520 0.146 56  0.5% linear 60 6140.124 57  0.5% tin coupled 77 549 0.105 58   1% linear 47 612 0.116 59  1% linear 62 645 0.106 60   1% tin coupled 68 504 0.108 61   2% linear25 393 0.160 62   2% linear 36 466 0.135 63   2% linear 65 554 0.124 64  5% linear 46 540 0.115 65   10% linear 44 581 0.107 *Mooney ML 1 + 4viscosity

It is desirable for tan delta to be as low as possible at 60° C. becausethe hysteresis of rubber is lower at lower tan delta values.Accordingly, tire tread compound that have lower tan delta values willhave less heat build-up and lower rolling resistance. As can be seenfrom Table 9, the incorporation of the PMS into the styrene-butadienerubber caused a reduction in tan delta at 60° C. The incorporation of0.25 weight percent of PMS into the styrene-butadiene rubber caused asignificant reduction in tan delta. The incorporation of higher level ofbound PMS into the styrene-butadiene rubber caused greater reduction intan delta values.

EXAMPLES 66-86

In this series of experiments tire tread compounds were make withstyrene-butadiene rubber that had various amounts of a mixture of3-(2-pyrrolidinoethyl)styrene and 4-(2-pyrrolidinoethyl)styrene (PES)incorporated therein. The amount of functionalized styrene monomer thatwas incorporated into the styrene-butadiene rubber is shown in Table 10.These tire tread compositions were made as described in Examples 49-65.The characterization of the tire tread compounds made are shown in Table10 (G′ was measure on uncured compounds and tan delta was measured oncured samples at 60° C.).

TABLE 10 Example PES Macrostructure ML-4* G′ (kPa) Tan delta 66   0%linear 41 500 0.177 67   0% linear 63 594 0.170 68 0.25% linear 25 5560.127 69 0.25% linear 32 597 0.114 70 0.25% linear 49 610 0.107 71 0.25%tin coupled 106 612 0.104 72  0.5% linear 19 590 0.119 73  0.5% linear30 609 0.110 74  0.5% linear 49 608 0.088 75  0.5% tin coupled 95 6270.094 76   1% linear 16 510 0.122 77   1% linear 42 620 0.105 78   1%tin coupled 81 570 0.091 79   2% linear 17 517 0.110 80   2% linear 42619 0.096 81   2% linear 60 619 0.085 82   2% tin coupled 65 572 0.09183   5% linear 25 605 0.091 84   5% tin coupled 47 554 0.101 85   5%linear 48 628 0.084 86   5% tin coupled 64 672 0.080 *Mooney ML 1 + 4viscosity

As has been explained it is desirable for the tan delta of tire treadcompounds to be as low as possible. As can be seen from Table 10, theincorporation of the PES into the styrene-butadiene rubber caused areduction in tan delta at 60° C. As can been seen by comparing Table 10to Table 9, the incorporation of PES into the styrene-butadiene rubbercaused a greater reduction in tan delta than did the incorporation ofPMS into the styrene-butadiene rubber.

EXAMPLES 87-91

In this series of experiments tire tread compounds that were loaded withsilica as a filler were make with styrene-butadiene rubber that hadvarious amounts of a mixture of 3-(2-pyrrolidinomethyl)styrene and4-(2-pyrrolidinomethyl)styrene (PMS) incorporated therein. The amount offunctionalized styrene monomer that was incorporated into thestyrene-butadiene rubber is shown in Table 11. These tire treadcompositions were made by mixing 55 phr of silica, 10 phr of processingoil, 3 phr of zinc oxide, 2 phr of stearic acid, 1.5 phr of antioxidant,1.5 phr of sulfenamide accelerator, and 1.4 phr of sulfur intostyrene-butadiene rubbers having different contents of boundfunctionalized styrene monomer. The characterization of the tire treadcompounds made are shown in Table 11 (G′ was measure on uncuredcompounds and tan delta was measured on cured samples at 60° C.).

TABLE 11 Example PMS ML-4* G′ (kPa) Tan delta 87  0% 41 890 0.235 88  1%47 800 0.157 89  5% 46 596 0.098 90 10% 44 674 0.086 91 20% 47 441 0.088*Mooney ML 1 + 4 viscosity

As has been explained it is desirable for the tan delta of tire treadcompounds to be as low as possible. As can be seen from Table 11, theincorporation of the PMS into the styrene-butadiene rubber caused areduction in tan delta at 60° C. Higher levels of PMS caused greaterreductions in tan delta. This series of experiments also that it ispossible to eliminate silica coupling agent from tire tread compoundsthat are made utilizing styrene-butadiene rubbers that contain a smallamount of bound PMS.

EXAMPLES 92-96

In this series of experiments tire tread compounds that were loaded withsilica as a filler were make with styrene-butadiene rubber that hadvarious amounts of a mixture of 3-(2-pyrrolidinomethyl)styrene and4-(2-pyrrolidinomethyl)styrene (PMS) incorporated therein. The amount offunctionalized styrene monomer that was incorporated into thestyrene-butadiene rubber is shown in Table 11. These tire treadcompositions were made by mixing 55 phr of silica, 10 phr of processingoil, 3 phr of zinc oxide, 2 phr of stearic acid, 1.5 phr of antioxidant,1.5 phr of sulfenamide accelerator, 1.4 phr of sulfur, and 4.4 phr ofsilica coupling agent into styrene-butadiene rubbers having differentcontents of bound functionalized styrene monomer. The characterizationof the tire tread compounds made are shown in Table 12 (G′ was measureon uncured compounds and tan delta was measured on cured samples at 60°C.).

TABLE 12 Example PMS ML-4* G′ (kPa) Tan delta 92  0% 41 754 0.173 93  1%47 720 0.132 94  5% 46 647 0.098 95 10% 44 617 0.081 96 20% 47 474 0.087(*Mooney ML 1 + 4 viscosity)

As has been explained it is desirable for the tan delta of tire treadcompounds to be as low as possible. As can be seen from Table 12, theincorporation of the PMS into the styrene-butadiene rubber caused areduction in tan delta at 60° C. Higher levels of PMS caused greaterreductions in tan delta. This series of experiments also that it ispossible to reduce the level of silica coupling agent in tire treadcompounds that are made utilizing styrene-butadiene rubbers that containa small amount of bound PMS and still realize good results.

EXAMPLES 97-102

In this series of experiments tire tread compounds that were loaded withsilica as a filler were make with styrene-butadiene rubber that hadvarious amounts of a mixture of 3-(2-pyrrolidinoethyl)styrene and4-(2-pyrrolidinoethyl)styrene (PES) incorporated therein. The amount offunctionalized styrene monomer that was incorporated into thestyrene-butadiene rubber is shown in Table 13. These tire treadcompositions were made by mixing 78 phr of silica, 28 phr of processingoil, 2.5 phr of zinc oxide, 2 phr of stearic acid, 3 phr of antioxidant,3 phr of siland coupler, 1.6 phr of sulfenamide accelerator, 1.9 phr ofguanadiene accelerator, and 2.1 phr of sulfur into styrene-butadienerubbers having different contents of bound functionalized styrenemonomer. The characterization of the tire tread compounds made are shownin Table 13 (G′ was measure on uncured compounds and tan delta wasmeasured on cured samples at 60° C.).

TABLE 13 Example PMS ML-4* G′ (kPa) Tan delta  97   0% 41 465 0.145  980.25% 49 645 0.151  99  0.5% 49 681 0.141 100   1% 42 657 0.120 101   2%42 749 0.102 102   5% 48 869 0.073 *Mooney ML 1 + 4 viscosity

As can be seen from Table 13, the incorporation of the PES into thestyrene-butadiene rubber caused a reduction in tan delta at 60° C.Higher levels of PMS caused greater reductions in tan delta. This seriesof experiments also that it is possible to reduce the level of silicacoupling agent in tire tread compounds that are made utilizingstyrene-butadiene rubbers that contain a small amount of bound PES andstill realize good results.

By utilizing styrene-butadiene rubber that has been modified byincorporation a small amount of PES therein tire tread compounds can bemade that exhibit lower hysteresis and that can be processed moreeasily. Silica loaded tire tread compounds can also be made withsignificantly lower levels of silica coupling agent. This is anextremely important benefit since silica coupling agents are expensiverelative to most other materials used in tire tread compounds. Theamount of silica coupling agent needed in such compounds can typicallybe reduced to a level within the range of 0 phs (parts by weight per 100parts by weight of silica) to 5 phs. More typically the level of silicacoupling agent is reduced to be within the range of 1 phs to 4 phs. Thelevel of silica coupling agent is most typically reduced to a levelwithin the range of 1 phs to 2 phs.

Functionalized styrene monomers which are of the structural formula:

wherein n represents an integer from 4 to about 10 are some of the mostbeneficial functionalized styrene monomers that can be utilized in thepractice of this invention. In such functionalized styrene monomers itis preferred form n to represent 4 or 6. PES (wherein n represents 4) isthe most preferred.

EXAMPLES 103-105 Linear Polymerization of 1% PES/19% Styrene/8%Butadiene

Premix Preparation

In the procedure used, 101.4 g of 93% PES in hexane was added to a20.27% butadiene in hexane premix cylinder via syringe under inertatmosphere to yield a solution with a monomer weight percent ratio of98.73% 1,3-butadiene and 1.27% PES. The cylinder contained 7,298.6 g1,3-Butadiene, 94.3 g PES and 28,607.1 g hexane. The cylinder contentswere mixed using a high shear mixer. Note that the PES can be added toeither butadiene or styrene in this manner. A styrene premix cylindercontaining 36,0009 of 20.98% styrene in hexane was then prepared.

Polymerization

The desired product was linear 1PES/19Styrene/80Butadiene SSBR copolymerwith a Mooney viscosity of 75 and a Tg midpoint of −35° C. madecontinuously. Although the desired product specifies 1% PES, thiscopolymer can be synthesized with a range of 0.25%−2% PES. To meet thesedesired product specifications the polymerization was performed underthe following operating conditions:

Monomer weight percent ratio into first reactor of1PES/19Styrene/80Butadiene

0.6897 mmoles n-butyllithium per 100 g monomer (Target Mn of 145,000)

75 parts 1,2-butadiene per million parts monomer

2.0 mmoles TMEDA per mole n-butyllithium

Reactor 1 Temp of 194° F.

Reactor 2 Temp of 190° F.

Total retention time of 1 hour

The continuous unit contains two one gallon CSTR's in series equippedwith mechanical agitators under inert atmosphere, followed by a fivegallon cement holding tank. Styrene, 1,3-butadiene and PES,1,2-butadiene, and TMEDA were brought together and then were added tothe first reactor where they met the n-butyllithium. After achievingsteady state, percent solids were used to monitor total monomerconversion, whereas GC analysis provided individual monomer consumption.GC results can be seen in Table 14.

The product was collected in a cement tank where it was terminated with1 mole isopropanol per mole n-BuLi (shortstop) and 1 part per hundredmonomer of Paratax (antioxidant). Polymer was air dried in a 130° F.oven for three days. Testing of the dry raw polymer includes MooneyLarge, DSC, GPC and NMR. Results from these tests can be seen in Tables15 and 16.

TABLE 14 Monomer Conversion via Gas Chromatograph Total % MonomerConversion % Butadiene % Styrene % Functional Mon. % Total Conv. 97.9596.36 99.88 97.67

TABLE 15 Linear Polymer Characterizations DSC (° C.) GPC Analysis ML +Onset Inflection End Mw/ 4 Tg Tg Tg Mn Mw Mz Mn 74 −42.02 −39.32 −36.67179,500 335,500 640,200 1.87

TABLE 16 NMR Data for Linear Polymer Trans Cis 1,4- 1,4- 1,2- StyreneSequence BD BD BD DVCH Styrene 1S 2-4S >/=5S PyrES 24.7 15.6 35.7 5.017.8 16.4 1.3 0.1 1.2

Coupled Polymerization of 1% PES/19% Styrene/80% Butadiene

The procedures outlined above were also used for coupled polymerizationswith tin tetrachloride, silicon tetrachloride, and a combination of thetwo. There are only slight variations in the operating conditions. Thecoupling agent was added in a ratio of 0.25 moles coupling agent permole n-butyllithium.

The 1% PES/19% styrene/80% 1,3-butadiene SSBR copolymer having a baseMooney viscosity of 35 was coupled continuously with a linear base toattain a coupled Mooney viscosity of 90 and a midpoint glass transitiontemperature (Tg) of −35° C. To meet these specifications thepolymerization was performed under the following operating conditions:

Monomer weight percent ratio into first reactor of1PES/19Styrene/80Butadiene

0.8091 mmoles n-butyllithium per 100 g monomer (Target Mn of 120,000)

75 parts 1,2-butadiene per million parts monomer

2.0 mmoles TMEDA per mole n-butyllithium

0.25 moles 2% coupling agent (both SnCl₄ and SiCl₄) in hexane per molen-butyllithium

Reactor 1 Temp of 194° F.

Reactor 2 Temp of 190° F.

Total retention time of 1 hour

The coupling agent is introduced to the polymerization in a high shearcement mixer located after the second reactor and before the cementholding tank. The hold time in the cement mixer is approximately fourminutes. Tables 17-19 include characterization data for thesecopolymers.

TABLE 17 Monomer Conversion via Gas Chromatograph Total % MonomerConversion % Butadiene % Styrene % Functional Mon. % Total Conv. 99.0398.65 99.88 98.97

TABLE 18 Linear Polymer Characterizations ML + 4 Base DSC (° C.) GPCAnalysis SnCl₄ Onset Inflection End Mw/ SiCl₄ Tg Tg Tg Mn Mw Mz Mn 42−38.5 −35.8 −33.0 127,000 274,800   647,800 2.16 88 −40.1 −36.7 −33.3147,900 424,100 1,471,000 2.87 74 −39.0 −36.2 −33.4 148,500 392,9001,158,000 2.65

TABLE 19 NMR Data for Linear Polymer Trans Cis 1,4- 1,4- 1,2- StyreneSequence BD BD BD DVCH Styrene 1S 2-4S >/=5S PyrES 21.3 15.3 37.4 5.020.1 18.3 1.4 0.5 0.9

Coupled Polymerization of 0.5% PES/19.5% Styrene/80% Butadiene

Once again, the procedures outlined above were used for coupledpolymerizations with tin tetrachloride, silicon tetrachloride. There areonly slight variations in the operating conditions. The coupling agentwas added in a ratio of 0.25 moles coupling agent per molen-butyllithium.

The 1% PES/19% styrene/80% 1,3-butadiene SSBR copolymer having a baseMooney viscosity of 35 was coupled continuously with a linear base toattain a coupled Mooney viscosity of 90 and a midpoint glass transitiontemperature (Tg) of −35° C. To meet these specifications thepolymerization was performed under the following operating conditions:

Monomer weight percent ratio into first reactor of1PES/19Styrene/80Butadiene

0.8091 mmoles n-butyllithium per 100 g monomer (Target Mn of 120,000)

75 parts 1,2-butadiene per million parts monomer 5-2.0 mmoles TMEDA permole n-butyllithium

0.25 moles 2% coupling agent (both SnCl₄ and SiCl₄) in hexane per molen-butyllithium

Reactor 1 Temp of 194° F.

Reactor 2 Temp of 190° F.

Total retention time of 0.5 hours

The coupling agent is introduced to the polymerization in a high shearcement mixer located after the second reactor and before the cementholding tank. The hold time in the cement mixer is approximately fourminutes. Tables 20-22 include characterization data for thesecopolymers.

TABLE 20 Monomer Conversion via Gas Chromatograph Total % MonomerConversion % Butadiene % Styrene % Functional Mon. % Total Conv. 98.5596.69 99.55 98.14

TABLE 21 Linear Polymer Characterizations ML + 4 Base DSC (° C.) SnCl₄Onset Inflection End GPC Analysis SiCl₄ Tg Tg Tg Mn Mw Mz Mw/Mn 32 −37.7−35.1 −32.4 120,100 189,400 276,200 1.58 73 −38.1 −34.8 −31.5 190,100468,500 960,800 2.46 86 −38.8 −35.6 −32.7 192,000 430,100 704,500 2.24

TABLE 22 NMR Data for Linear Polymer Trans Cis 1,4- 1,4- 1,2- StyreneSequence BD BD BD DVCH Styrene 1S 2-4S >/=5S PyrES 22.1 15.5 37.5 4.919.6 17.5 1.9 0.2 0.4

EXAMPLES 106-108

High Trans SBR

Polymerization of styrene, 1-pyrrolidino-ethyl styrene (PES) andbutadiene was carried out in a one-gallon glass bowl batch reactor,under a blanket of nitrogen, equipped with a mechanical stirrer andtemperature control via cooling water and low pressure steam. Bothbutadiene and styrene premixes contained approximately 20% monomerdissolved in hexane. The reactor was charged with 1% PES, 9% styrene inhexane and 90% butadiene in hexane to synthesize the appropriatepolymer. The catalyst was added at room temperature, and within minutesof addition, the reactor temperature was 90° C. The catalyst system forthis polymer consisted of an alkylated Barium diethyleneglycolethylether (BaDEGEE) and Trioctyl aluminum (TOA) in a 1 (BaDEGEE) to 4(TOA) ratio and n-butylithium. The addition of this catalyst iscrictical for a successful polymerization. The alkylated BaDEGEE and TOAsolution was prepared by added the appropriate amount of TOA to BaDEGEEand heated for 30 minutes at 70° C. Pyrrolidine and TMEDA can also beused as a modifier in this catalyst in a ratio of 1/1 amine/BaDEGEE, andthey are typically added in this alkylation step. Here, 0.80 mmol ofBaDEGEE per 100 grams of polymer was used to intiate polymerization. Thealkylated BaDEGEE/TOA solution (with or without amine present) was addedto a clean bottle and the correct amount of n-BuLi (in a ratio of 3n-BuLi to 1 BaDEGEE) was added. The final solution had a ratio of1/4/3/1 BaDEGEE/TOA/n-BuLi/amine (if used). This solution was shaken forseveral minutes at room temperature, and then it was injected as theinitiator. Samples were taken over the course of the reaction todetermine monomer conversion. According to gas chromatography, the PESmonomer appeared to react much faster than the butadiene or styrene, seeFIG. 1. All reactions were short-stopped with denatured ethanol, and2,6-ditertbutylphenol was added to the polymer cement. The polymer wasthen dried for several days in a hot oven to make sure all solvent hadevaporated. Table 1 summarizes the data for this system:

High Trans IBR

Using the same procedure and catalyst system as above, polymerization ofPES, isoprene and butadiene was carried out. The only difference wasthat the reactor was charged with 1% PES, 9% isoprene and 90% butadiene.All other conditions were identical. FIG. 2 illustrates monomerconversion versus time. Polymer characteristics are shown in Table 1.

High Trans SIBR

Using the same procedure and catalyst system outlined above,polymerization of PES, styrene, isoprene and butadiene was carried out.The only difference was that the reactor was charged with 1% PES, 9%isoprene +styrene (2.5, 4.5 and 7.5% isoprene) and 90% butadiene. Allother conditions were identical.

TABLE 23 Polymer characteristics for PES containing high trans polymersTg Tg Sample (onset) (midpt.) Tm Mn Mw PDI ML + 4 1/9/90 −83.4° C.−76.0° C. 24.2° C. 135K 191K 1.42 57 HTPESSBR 10/90 −86.0° C. −79.7° C.17.6° C. 102K 164K 1.61 66 HTSBR

TABLE 24 NMR Results for PyrES High Trans polymers Trans Cis Sample1,4-BD 1,4-BD 1,2-BD Styrene PyrES 1/9/90 HTPESSBR 76.0 13.2 3.4 6.5 0.910/90 HTSBR 75.2 13.8 3.5 7.5 —

EXAMPLE 109

In this experiment, a low vinyl polybutadiene containing 5%pyrrolidinoethylstyrene (PES) was prepared. In the procedure, 1000 gramsof a silica/alumina/molecular sieve dried premix containing 19 weightpercent of 1,3-butadiene in hexanes was charged into a one-gallon (3.8liter) reactor. Then, 10.2 grams of a 93% PES was added to the reactor.The PES used consisted of a 93% mixture of 3-(2-pyrrolidinoethyl)styreneand 4-(2-pyrrolidinoethyl)styrene and a 7% mixture of3-(2-pyrrolidinoethyl)-1-ethylbenzene and4-(2-pyrrolidinoethyl)-1-ethylbenzene. The polymerization was initiatedwith 1.9 ml. of 1 M n-butyllithium (in hexane). The polymerization wascarried out at 90° C. for 90 minutes. The progress of the polymerizationwas monitored by analyzing the residual monomer contained in thepolymerization mixture using a GC. The GC analyses indicated that thePES co-polymerized randomly with 1,3-butadiene and all monomers wereconsumed after 60 minutes. The polymer cement was then shortstopped withethanol and was subsequently removed from the reactor and stabilizedwith 1 phm of antioxidant. After evaporating the hexane solvent, theresulting polymer was dried in a vacuum oven at 50° C.

The PES-butadiene copolymer produced was determined to have a glasstransition temperature (Tg) at −83° C. The Mooney viscosity (ML-4) at100° C. for this polymer was determined to be 60.

EXAMPLES 110-112

In these experiments, low vinyl polybutadienes contained 2% and 1% PESwere prepared using a procedure similar to the procedures described inExample 109 except that the amount of PES utilized was 1% or 2% ratherthan 5%. The glass transition temperature (Tg) and vinyl content of theresulting rubbery polymers are listed in Table 1.

TABLE 25 Example PES Tg Vinyl Content 110 5% −83° C. 18% 111 2% −92° C.11% 112 1% −94° C.  9%

COMPARATIVE EXAMPLE 113

In this experiment, a low vinyl polybutadiene rubber was prepared usingthe procedure as described in Example 109 except that no PES wascopolymerized into the polymer. The glass transition temperature (Tg) ofthe resulting polybutadiene rubber was −98° C. and its vinyl content was8%.

EXAMPLE 114

In this experiment, a low vinyl polyisoprene containing 5% PES wasprepared. The procedure described in Example 109 was used except thatisoprene was used as the main monomer and the polymerization wasconducted at a temperature of 65° C. The GC analyses of the residualmonomers indicated that the PES monomer randomly copolymerized with theisoprene throughout the polymerization and that all monomers wereconsumed after 100 minutes of polymerization time. The glass transitiontemperature (Tg) of the polyisoprene rubber was −56 and it had a MooneyML-4 viscosity of 82.

EXAMPLE 115

In this experiment, a low vinyl polyisoprene rubber containing 1% boundPES was prepared. The procedure described in Example 114 was used exceptin this experiment 1% of the PES monomer was copolymerized into thepolymer. Again, GC analyses of the residual monomers showed that PES wasrandomly distributed along the polymer chains. The glass transitiontemperature and Mooney ML-4 viscosity of the resulting polyisoprenerubber were −63.4° C. and 70, respectively.

COMPARATIVE EXAMPLE 116

In this experiment, a low vinyl polyisprene rubber was preparedutilizing a procedure that is similar to the one described in Example114 except that no PES was was copolymerized into the polymer. The glasstransition temperature and vinyl content of the resulting polyisoprenerubber were −65° C. and 8%, respectively.

EXAMPLE 117

Vinylbenzylic anion is generated from vinyltoluene with metal salts ofamines, such as lithium diisopropylamine (LDA), sodium diisopropylamine,lithium diethylamine, lithium methylamine, in the presence of freeprimary and secondary amines, which can be the same or different fromthe metal amide. Accordingly, 2.02 grams of diisopropylamine (20 mmol)was dissolved in 20 ml of dried tetrahydrofuran (THF) under a nitrogenatmosphere with 6.5 ml of 1.6 M BuLi (10 mmol) solution in hexane beingadded to generate the lithium amide in situ. Then 1.2 grams ofvinyltoluene (10 mmol) was added in one portion. The presence of thefree amine prevented polymerization and made the metal amide a strongeragent for metallation. The desired vinylbenzylic anion was generated inan equilibrium with the amide.

EXAMPLE 118

Reaction of the vinylbenzylic anion synthesized in Example 117 with ahalogenated reagent, such as trimetylchlorosilane, producesfunctionalized styrene monomer. Accordingly, a solution containing 1.2grams of trimethylchlorosilane (11 mmol) in 5 ml THF was slowly addedover a period of 3 hours at 20° C. to the vinylbenzylic anion solutionmade in Example 117. Analysis by gas chromatography showed a 50% yieldwith peaks identified as regents and both mono and bis-adducts. Afterwashing with dilute a dilute hydrochloric acid (HCl) solution 3 times,the solvent was evaporated and the producted was distilled under vacuum.NMR confirmed that the fraction collected at 100-120° C. and 0.5 mmHg ofvacuum contained trimethylsilylmethylstyrene as a major product.

EXAMPLE 119

In this experiment the synthesis of trimethylsilylmethylstyrene wasscaled-up to a 2-liter flask. After purging the flask with nitrogen gasfor one hour, 500 ml dried THF was added and purged with nitrogen forhalf an hour. Then, 630 ml of 1.6 M BuLi solution in hexane (1.0 mol)was added and the flasked was cooled to 0° C. and then 280 ml of drieddiisopropylamine (2.0 mol) was added dropwisely to the flask, followedby addition of 132 ml of p-methyl-styrene (1.0 mol). The temperature wasmaintained at about 20° C. and 120 grams of trimethylchlorosilane (1.1mol) in 100 ml THF was slowly added over a period of 4 hours. Afterwashing three times with a dilute aqueous HCl solution, the organicphase was dried and concentrated. Distillation under vacuum gave thedesired trimethylsilylmethylstyrene compound. Both GC and NMR confirmedthe existence of the functional groups.

EXAMPLE 120

The general procedure described in Example 119 can be used to prepareother functionalized styrene monomers with other halogenated reagents.Thus, in the procedure described in Example 119, by substituting 1.1mole of chlorodiphenylphosphine (243 g) for the 1.1 mole oftrimethylchlorosilane (120 g), a new functional styrene(diphenyl-vinylbenzyl-phosphine) can be synthesized. The method providesa general monomer synthesis methodology to generate an vinylbenzylanions using vinyltoluene and various elctrophile agents selected fromCl—Si—(CH₃)₃, Cl—(CH₂)₃—Si—(OCH₃)₃, Cl—(CH₂)₃—Si—(CH₃)—(OCH₃)₂,Cl—P—Ph₂, Cl—P-Et₂, Cl—P-Cyclohexyl₂, Cl—(CH₂)₂—N—(C₄H₈),Cl—(CH₂)₂—N—(CH₃)₂, Cl—(CH₂)₂—O—CH₃, Cl—(CH₂)₂—O—(CH₂CH₃)₂,Cl—Sn—(C₄H₉)₃, Cl—Sn—(CH₃)₃, and Br—Sn—(C₄H₉)₃.

EXAMPLE 121

In this experiment, a trimethylsilylmethyl styrene/styrene/1,3-butadieneterpolymer was prepared. In the procedure utilized, 1930 grams of asilica/alumina/molecular sieve dried premix containing 21.31 weightpercent trimethylsilylmethyl styrene (TMSMS), styrene and 1,3-butadienein hexanes was charged into a one-gallon (3.8 liters) reactor. The TMSMSto styrene to 1,3-butadiene ratio was 1:16:83. In the procedure used,0.49 ml of neat N,N, N′,N′-tetramethylethylenediamine (TMEDA) and 2.3 mlof 0.97 M n-butyl lithium (n-BuLi) in hexane were added to the reactor,respectively. The molar ratio of TMEDA to n-BuLi was 1.5:1. Thepolymerization was carried out at 70° C. for 150 minutes. The GCanalysis of the residual monomer contained in the polymerization mixtureindicated that the all monomers were consumed at that time, and thepolymer cement was then shortstopped with ethanol and subsequentlyremoved from the reactor and stabilized with 1 phm of antioxidant. Afterevaporating hexane, the resulting polymer was dried in a vacuum oven at50° C. The GC analysis of the residual monomer with respect to thepolymerization time also indicated that even thorough TMSMS polymerizedmuch slower than the 1,3-butadiene and styrene, most of TMSMS wasrandomly distributed along the polymer chain.

The TMSMS-styrene-butadiene terpolymer produced was determined to have aglass transition temperature (Tg) at −32° C. It was also determined tohave a microstructure which contained 49.7 percent 1,2-polybutadieneunits, 31.2 percent 1,4-polybutadiene units, 16.3 percent randompolystyrene units and 0.7 percent of TMSMS units. The Mooney viscosity(ML-4) at 100° C. of the polymer was determined to be 62.

EXAMPLE 122

In this experiment, an emulsion a styrene/butadiene/pyrrolidinoethylstyrene (PES) terpolymer was prepared. In the procedure used, 7.29 lbs.of soft water, 4.76 grams of sodium naphthalenesulfonate-formaldehydedispersant (Daxad 14B from Hampshire Chemical Co., 47.5% active), 7.2gms. of tripotassium phosphate, 140 grams of disproportionated rosinacid (potassium salt, 20% solution in water at pH 9.5), and 532 grams ofC14-18 and C16-18 unsaturated fatty acids (potassium salt, 10% solutionin water at pH 9.5) were charged into a 2-gallon stainless steelreactor. Prior to charging to the reactor, the pH of the solution wasadjusted to 10.2-10.8 by the addition of a 10% aqueous potassiumhydroxide solution. Then, 100 grams of soft water, 0.32 grams ofethylenediaminetetraacetic acid/ferric sodium complex (Akzo NobelChemicals Co.) and 1.08 grams of sodium formaldehyde sulfoxylate wereadded. Then, 580 grams of styrene, 22.5 grams of PES (92% purity), and4.5 grams of tert-dodecylmercaptan were added.

The reactor was evacuated for about 30 minutes and 1400 grams of1,3-butadiene was added. At a temperature of 10° C., 1.82 grams ofpinane hydroperoxide (44% active) was added. The emulsion polymerizationwas initiated at a temperature of 10° C. with the reactor beingagitation at 300 rpm. After 7 hours at a conversion of about 65% thepolymerization was shortstopped by the addition of a solution of 160grams of water, 0.64 grams of potassium hydroxide, 1.5 grams of thesodium salt of N,N-diethyldithiocarbamate(40% active), and 0.71 grams ofN,N-diethylhydroxylamine (85% active).

After stripping off the unreacted monomers under vacuum using a rotaryevaporator, a sample of the latex (about 24.7% solids) with 1 part addedof Polystay® C antioxidant per 100 parts dry rubber and 1 part added ofPolygard antioxidant (Uniroyal Chemical Co.) per 100 parts dry rubberwas coagulated and the rubber crumb dried. The coagulation was carriedout using 3000 grams of water, 30 grams of sodium chloride, and 1 gramof an ethylene amine mixture with vigorous agitation at 160-180° F. A 10weight percent aqueous sulfuric acid solution was slowly added to thecoagulation solution to maintain the pH within the range of 3 to 4. Theresulting rubber crumb was washed with water and dried at 150° F. in aforced air oven.

The Mooney viscosity at 100° C. of the rubber was 44. The bound styrenecontent and PES content of the polymer were determined by NMR to be24.0% and 0.9% respectively. The midpoint glass transition temperatureof the rubber was determined by DSC (Differential Scanning Calorimetry)to be −52° C. and the onset glass transition temperature was determinedto be −56° C.

COMPARATIVE EXAMPLE 123

In this experiment, a control emulsion styrene/butadiene copolymer wasmade in a 2-gallon stainless steel reactor using the procedure describedin Example 122 except that no PES was used and 600 grams of styrene and5.1 grams of tert-dodecylmercaptan were used. After 6.25 hours ofpolymerization time and approximately 65% conversion, the emulsionpolymerization was shortstopped. After coagulation and drying the rubbercrumb of the emulsion styrene/butadiene copolymer exhibited a Mooneyviscosity (100° C.) of 45, a midpoint glass transition temperature of−53.6° C. and an onset glass transition temperature of −56° C. NMRshowed a bound styrene level of 23.2%.

EXAMPLE 124

In this experiment, an emulsion styrene/butadiene/pyrrolidinoethylstyrene (PES) terpolymer was prepared in a larger reactor. In theprocedure utilized, 40.1 lbs. of soft water, 33 grams of sodiumnaphthalenesulfonate-formaldehyde dispersant (Daxad 14B from HampshireChemical Co., 47.5% active), 25.5 grams of potassium chloride, 767 gramsof disproportionated rosin acid (potassium salt, 20% solution in waterat pH 9.5), 2927 grams of C14-18 and C16-18 unsaturated mixed fattyacids (potassium salt, 10% solution in water at pH 9.5), and 5.82 gramsof tripotassium phosphate were charged into a 10-gallon stainless steelreactor. Prior to charging to the reactor, the pH of the solution wasadjusted to 10.2-10.8 with 20% potassium hydroxide. Next, 440 grams ofsoft water, 1.26 grams of ethylenediaminetetraacetic acid, ferric sodiumcomplex (Akzo Nobel Chemicals Co.), and 7.75 grams of sodiumformaldehyde sulfoxylate were added. Then, 3245 grams of styrene, 59.8grams of PES (92% purity by GC), and 16.0 grams of tertiarydodecylmercaptan were added. The reactor was evacuated for 15 minutes,and 7700 grams of 1,3-butadiene was added. At 10° C., 10 grams of pinanehydroperoxide (55% active) was added. The emulsion polymerization wasinitiated at a temperature of 10° C. with the reactor being agitated ata speed of 250 rpm with two AFT blades. After 6.25 hours and about 65%conversion, the polymerization was shortstopped with a solution of 880grams of soft water and 44 grams of isopropylhydroxylamine (15% active).

After stripping off the unreacted monomers under vacuum, 1 part ofPolystay® C antioxidant per 100 parts of dry rubber and 1 part ofPolygard (Uniroyal Chemical Co.) per 100 parts dry rubber were added tothe sample of the latex and it was coagulated. The rubber crumb waswashed with water and dried at 150° F. in a forced air oven. Thecoagulation was carried out using a mixture containing 3000 grams softwater, 30 grams of sodium chloride and 1 gram of ethylene amine withvigorous agitation at 160-180° F. Sulfuric acid (10% wt.) was added tothe coagulation solution to maintain the pH at 3-4 as the latex wassloely added. The Mooney viscosity (100° C.) of the rubber was 107. Thebound styrene content (by NMR) was 23.8% and the PES was 0.4% (by NMR).A colorimetric analysis method showed PES content of 0.47 weightpercent.

EXAMPLE 125

In this experiment, an emulsionstyrene/butadiene/3-(2-pyrrolidino-1-methyl ethyl)-1-alpha-methylstyrene (PAMS) terpolymer was prepared. To a 2-gallon stainless steelreactor, 7.29 lbs. of soft water, 4.76 grams of sodiumnaphthalenesulfonate-formaldehyde dispersant (Daxad 14B from HampshireChemical Co., 47.5% active), 7.2 grams of tripotassium phosphate, 140grams of disproportionated rosin acid (potassium salt, 20% solution inwater at pH 9.5), and 532 grams of C14-18 and C16-18 unsaturated fattyacids (potassium salt, 10% solution in water at pH 9.5) were charged.Prior to charging to the reactor, the pH of the solution was adjusted to10.2-10.8 with 10% potassium hydroxide. Next, 100 grams of soft water,0.32 gram of ethylenedidaminetetraacetic acid/ferric sodium complex(Akzo Nobel Chemicals Co.), and 1.08 grams of sodium formaldehydesulfoxylate were added. Then, 580 grams of styrene, 20 grams of3-(2-pyrrolidino-1-methyl ethyl)-lalpha-methyl styrene (PAMS, 100%purity), and 4.4 grams of tert-dodecylmercaptan were added. The reactorwas evacuated for about 30 minutes, and 1400 grams of 1,3-butadiene wasadded. At 10° C., 1.82 grams of pinane hydroperoxide (44% active) wasadded. The emulsion polymerization was initiated at 10° C. with reactoragitation using two AFT blades at 300 rpm. After 5 hours and about 65%conversion, the polymerization was shortstopped with a solution of 8grams isopropylhydroxylamine (15% active) and 180 grams of soft water.After stripping off the unreacted monomers under vacuum using a rotaryevaporator, a sample of the latex with 1 part added Polystay® Cantioxidant per 100 parts dry rubber and 1 part added of Polygard(Uniroyal Chemical Co.) per 100 parts dry rubber was coagulated and therubber crumb dried. The coagulation was carried out using 3000 grams ofwater, 30 grams of sodium chloride, and 1 gram of ethylene amine mixturewith vigorous agitation at a temperature of 160-180° F. A 10 weightpercent aqueous sulfuric acid solution was added to the coagulationsolution to maintain the pH at 3-4 as the latex was added slowly. Theresulting rubber crumb was washed with water and dried at 150° F. in aforced air oven. The Mooney viscosity (100° C.) of the rubber was 43.5.The bound styrene content (by NMR) was 22.9% and the PAMS was 0.4%(nmr). The midpoint glass transition temperature was −55° C. by DSC(Differential Scanning Calorimetry) and the onset glass transitiontemperature was −58° C.

Variations in the present invention are possible in light of thedescription of it provided herein. While certain representativeembodiments and details have been shown for the purpose of illustratingthe subject invention, it will be apparent to those skilled in this artthat various changes and modifications can be made therein withoutdeparting from the scope of the subject invention. It is, therefore, tobe understood that changes can be made in the particular embodimentsdescribed which will be within the full intended scope of the inventionas defined by the following appended claims.

What is claimed is:
 1. A process for synthesizing a rubbery polymer thatcomprises copolymerizing at least one conjugated diolefin monomer and atleast one functionalized monomer in an organic solvent at a temperaturewhich is within the range of 20° C. to about 100° C., wherein thepolymerization is initiated with an anionic initiator, wherein thepolymerization is conducted in the absence of conventional polarmodifiers, and wherein the functionalized monomer is of the structuralformula:

wherein the R′ groups in repeat units and in different repeat units canbe the same or different and represent hydrogen atoms or alkyl groupscontaining from 1 to about 4 carbon atoms, wherein x represents aninteger from 1 to about 10, and wherein the R groups in repeat units andin different repeat units can be the same or different and representalkyl groups containing from 1 to about 10 carbon atoms or alkoxy groupscontaining from 1 to about 10 carbon atoms.
 2. A rubbery polymer whichis comprised of repeat units that are derived from (1) at least oneconjugated diolefin monomer, and (2) at least one functionalized monomerof the structural formula:

wherein the R′ groups in repeat units and in different repeat units canbe the same or different and represent hydrogen atoms or alkyl groupscontaining from 1 to about 4 carbon atoms, wherein x represents aninteger from 1 to about 10, and wherein the R groups in repeat units andin different repeat units can be the same or different and representalkyl groups containing from 1 to about 10 carbon atoms or alkoxy groupscontaining from 1 to about 10 carbon atoms.
 3. A rubbery polymer asspecified in claim 2 wherein x represents an integer from 1 to
 4. 4. Arubbery polymer as specified in claim 3 wherein R′ represents hydrogenatoms and/or methyl groups.
 5. A rubbery polymer as specified in claim 3wherein R′ represents hydrogen atoms.
 6. A rubbery polymer as specifiedin claim 4 wherein R represents alkoxy groups.
 7. A rubbery polymer asspecified in claim 5 wherein R represents alkoxy groups containing from1 to 4 carbon atoms.
 8. A rubbery polymer as specified in claim 2 whichis further comprised of repeat units that are derived from styrene.
 9. Arubbery polymer as specified in claim 2 wherein the conjugated diolefinmonomer is 1,3-butadiene.
 10. A rubbery polymer as specified in claim 2wherein the conjugated diolefin monomer is isoprene.
 11. A rubberypolymer as specified in claim 2 wherein the repeat units are derivedfrom 0.1 phm to about 1 phm of the functionalized monomer.
 12. A rubberypolymer as specified in claim 2 wherein the repeat units are derivedfrom 0.3 phm to about 0.7 phm of the functionalized monomer.